1
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Kuttruff J, Nabben D, Zimmermann AC, Ryabov A, Baum P. Terahertz control and timing correlations in a transmission electron microscope. SCIENCE ADVANCES 2024; 10:eadl6543. [PMID: 38924397 PMCID: PMC11204200 DOI: 10.1126/sciadv.adl6543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 05/17/2024] [Indexed: 06/28/2024]
Abstract
Ultrafast electron microscopy provides a movie-like access to structural dynamics of materials in space and time, but fundamental atomic motions or electron dynamics are, so far, too quick to be resolved. Here, we report the all-optical control, compression, and characterization of electron pulses in a transmission electron microscope by the single optical cycles of laser-generated terahertz light. This concept provides isolated electron pulses and merges the spatial resolution of a transmission electron microscope with the temporal resolution that is offered by a single cycle of laser light. We also report the all-optical control of multi-electron states and find a substantial two-electron and three-electron anticorrelation in the time domain. These results open up the possibility to visualize atomic and electronic motions together with their quantum correlations on fundamental dimensions in space and time.
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Affiliation(s)
| | | | | | - Andrey Ryabov
- Universität Konstanz, Fachbereich Physik, 78464 Konstanz, Germany
| | - Peter Baum
- Universität Konstanz, Fachbereich Physik, 78464 Konstanz, Germany
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2
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Kim H, Kang C, Jang D, Roh Y, Lee SH, Lee JW, Sung JH, Lee SK, Kim KY. Ionizing terahertz waves with 260 MV/cm from scalable optical rectification. LIGHT, SCIENCE & APPLICATIONS 2024; 13:118. [PMID: 38802347 PMCID: PMC11130333 DOI: 10.1038/s41377-024-01462-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 04/05/2024] [Accepted: 04/20/2024] [Indexed: 05/29/2024]
Abstract
Terahertz (THz) waves, known as non-ionizing radiation owing to their low photon energies, can actually ionize atoms and molecules when a sufficiently large number of THz photons are concentrated in time and space. Here, we demonstrate the generation of ionizing, multicycle, 15-THz waves emitted from large-area lithium niobate crystals via phase-matched optical rectification of 150-terawatt laser pulses. A complete characterization of the generated THz waves in energy, pulse duration, and focal spot size shows that the field strength can reach up to 260 megavolts per centimeter. In particular, a single-shot THz interferometer is employed to measure the THz pulse duration and spectrum with complementary numerical simulations. Such intense THz pulses are irradiated onto various solid targets to demonstrate THz-induced tunneling ionization and plasma formation. This study also discusses the potential of nonperturbative THz-driven ionization in gases, which will open up new opportunities, including nonlinear and relativistic THz physics in plasma.
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Affiliation(s)
- Hyeongmun Kim
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
- Department of Physics and Optoelectronics Convergence Research Center, Chonnam National University, Gwangju, 61186, Korea
| | - Chul Kang
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea.
| | - Dogeun Jang
- Pohang Accelerator Laboratory, POSTECH, Pohang, 37673, Korea
| | - Yulan Roh
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
| | - Sang Hwa Lee
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Joong Wook Lee
- Department of Physics and Optoelectronics Convergence Research Center, Chonnam National University, Gwangju, 61186, Korea
| | - Jae Hee Sung
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Seong Ku Lee
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Ki-Yong Kim
- Institute for Research in Electronics and Applied Physics; Department of Physics, University of Maryland, College Park, Maryland, 20742, USA.
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3
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Liu L, Heng X, Xuan H. 205-240 GHz free-space-to-fiber mode adapter with an 80% mode conversion efficiency. APPLIED OPTICS 2024; 63:3187-3191. [PMID: 38856466 DOI: 10.1364/ao.516566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/26/2024] [Indexed: 06/11/2024]
Abstract
In this work, we propose an integrated terahertz mode adapter that couples broadband terahertz radiation from free-space to hollow-core fiber with a high mode conversion efficiency (Gaussian beam-to-T E 01) of up to 80%. The adapter consists of a pyramidal horn antenna, a broadband mode converter, and a conical horn. The simulation results indicate that the T E 01 mode in the hollow-core fiber can be efficiently excited by the terahertz mode adapter. The terahertz mode adapter successfully achieved a wide operating bandwidth of more than 15.7% ranging from 205 to 240 GHz in our simulation.
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4
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Othman MAK, Gabriel AE, Snively EC, Kozina ME, Shen X, Ji F, Lewis S, Weathersby S, Vasireddy P, Luo D, Wang X, Hoffmann MC, Nanni EA. Improved temporal resolution in ultrafast electron diffraction measurements through THz compression and time-stamping. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:024311. [PMID: 38655563 PMCID: PMC11037933 DOI: 10.1063/4.0000230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 04/05/2024] [Indexed: 04/26/2024]
Abstract
We present an experimental demonstration of ultrafast electron diffraction (UED) with THz-driven electron bunch compression and time-stamping that enables UED probes with improved temporal resolution. Through THz-driven longitudinal bunch compression, a compression factor of approximately four is achieved. Moreover, the time-of-arrival jitter between the compressed electron bunch and a pump laser pulse is suppressed by a factor of three. Simultaneously, the THz interaction imparts a transverse spatiotemporal correlation on the electron distribution, which we utilize to further enhance the precision of time-resolved UED measurements. We use this technique to probe single-crystal gold nanofilms and reveal transient oscillations in the THz near fields with a temporal resolution down to 50 fs. These oscillations were previously beyond reach in the absence of THz compression and time-stamping.
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Affiliation(s)
- Mohamed A. K. Othman
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Annika E. Gabriel
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Emma C. Snively
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Michael E. Kozina
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Fuhao Ji
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Samantha Lewis
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Stephen Weathersby
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Praful Vasireddy
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Duan Luo
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, USA
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5
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Yu X, Zeng Y, Bai Y, Song L, Tian Y. Hollow metal tubes for efficient electron manipulation using terahertz surface waves. OPTICS EXPRESS 2024; 32:3076-3084. [PMID: 38297538 DOI: 10.1364/oe.509993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 12/30/2023] [Indexed: 02/02/2024]
Abstract
Compact electron sources have been instrumental in multidiscipline sciences including fundamental physics, oncology treatments, and advanced industries. Of particular interest is the terahertz-driven electron manipulation that holds great promise for an efficient high gradient of multi-GeV/m inside a regular dielectric-lined waveguide (DLW). The recent study relying on terahertz surface waves has demonstrated both high terahertz energy and improved coupling efficiency with the DLW. However, the large energy spread pertaining to the laser-induced electron pulse impedes the practical use of the system. Here, we propose a scheme for extending the idea of surface-wave-driven electron manipulation to mature electron sources such as commercial direct-current and radio-frequency electron guns. By using a simple hollow cylinder tube for electron transmission, we show that the electron energy modulation can reach up to 860 keV, or compress the electron pulse width to 15 fs using a 2.9 mJ single-cycle terahertz pulse. The trafficability of the hollow tube also allows for a cascade of the system, which is expected to pave the way for compact and highly efficient THz-driven electron sources.
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6
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Tóth G, Illés G, Nazymbekov G, Mbithi N, Almási G, Hebling J. Possibility of CO 2 laser-pumped multi-millijoule-level ultrafast pulse terahertz sources. Sci Rep 2024; 14:999. [PMID: 38200090 PMCID: PMC10781974 DOI: 10.1038/s41598-023-51139-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 12/31/2023] [Indexed: 01/12/2024] Open
Abstract
In the last decade, intense research has been witnessed on developing compact, terahertz (THz) driven electron accelerators, producing electrons with a sub-MeV-few tens of MeV energy. Such economical devices could be used in scientific and material research and medical treatments. However, until now, the extremely high-energy THz pulses needed by the THz counterparts of the microwave accelerators were generated by optical rectification (OR) of ultrafast Ti:sapphire or Yb laser pulses. These lasers, however, are not very effective. Because of this, we use numerical simulations to investigate the possibility of generating high-energy THz pulses by the OR of pulses produced by CO2 lasers, which can have high plug-in efficiency. The results obtained supposing optical rectification (OR) in GaAs demonstrate that consideration of the self-phase-modulation (SPM) and the second-harmonic-generation (SHG) processes is indispensable in the design of CO2 laser-based THz sources. More interestingly, although these two processes hinder achieving high laser-to-THz conversion efficiency, they can still surpass the 1.5% value, ensuring high system efficiency and making the CO2 laser OR system a promising THz source. Our finding also has important implications for other middle-infrared laser-pumped OR-based THz sources.
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Affiliation(s)
- György Tóth
- Institute of Physics, University of Pécs, Pecs, 7624, Hungary.
- Szentágothai Research Centre, University of Pécs, 7624, Pecs, Hungary.
| | - Gergő Illés
- Institute of Physics, University of Pécs, Pecs, 7624, Hungary
| | | | - Nelson Mbithi
- Institute of Physics, University of Pécs, Pecs, 7624, Hungary
- Natural Sciences Department, Garissa University, Garissa, 1801, Kenya
| | - Gábor Almási
- Institute of Physics, University of Pécs, Pecs, 7624, Hungary
- Szentágothai Research Centre, University of Pécs, 7624, Pecs, Hungary
| | - János Hebling
- Institute of Physics, University of Pécs, Pecs, 7624, Hungary.
- Szentágothai Research Centre, University of Pécs, 7624, Pecs, Hungary.
- HUN-REN-PTE High-Field Terahertz Research Group, Pecs, Hungary.
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7
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Matlis NH, Zhang Z, Demirbas U, Rentschler C, Ravi K, Youssef M, Cirmi G, Pergament M, Edelmann M, Mohamadi SM, Reuter S, Kärtner FX. Precise parameter control of multicycle terahertz generation in PPLN using flexible pulse trains. OPTICS EXPRESS 2023; 31:44424-44443. [PMID: 38178514 DOI: 10.1364/oe.503480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/23/2023] [Indexed: 01/06/2024]
Abstract
The low (sub %) efficiencies so-far demonstrated for nonlinear optical down-conversion to terahertz (THz) frequencies are a primary limiting factor in the generation of high-energy, high-field THz-radiation pulses (in particular narrowband, multicycle pulses) needed for many scientific fields. However, simulations predict that far higher conversion efficiencies are possible by use of suitably-optimized optical sources. Here we implement a customized optical laser system producing highly-tunable trains of infrared pulses and systematically explore the experimental optimization of the down-conversion process. Our setup, which allows tuning of the energy, duration, number and periodicity of the pulses in the train, provides a unique capability to test predictions of analytic theory and simulation on the parameter dependences for the optical-to-THz difference-frequency generation process as well as to map out, with unprecedented precision, key properties of the nonlinear crystal medium. We discuss the agreements and deviations between simulation and experimental results which, on the one hand, shed light on limitations of the existing theory, and on the other hand, provide the first steps in a recipe for development of practical, high-field, efficiency-optimized THz sources.
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8
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Garriga Francis KJ, Zhang XC. Local measurement of terahertz field-induced second harmonic generation in plasma filaments. FRONTIERS OF OPTOELECTRONICS 2023; 16:44. [PMID: 38091154 PMCID: PMC10719236 DOI: 10.1007/s12200-023-00095-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/29/2023] [Indexed: 12/17/2023]
Abstract
The concept of Terahertz Field-Induced Second Harmonic (TFISH) Generation is revisited to introduce a single-shot detection scheme based on third order nonlinearities. Focused specifically on the further development of THz plasma-based sources, we begin our research by reimagining the TFISH system to serve as a direct plasma diagnostic. In this work, an optical probe beam is used to mix directly with the strong ponderomotive current associated with laser-induced ionization. A four-wave mixing (FWM) process then generates a strong second-harmonic optical wave because of the mixing of the probe beam with the nonlinear current components oscillating at THz frequencies. The observed conversion efficiency is high enough that for the first time, the TFISH signal appears visible to the human eye. We perform spectral, spatial, and temporal analysis on the detected second-harmonic frequency and show its direct relationship to the nonlinear current. Further, a method to detect incoherent and coherent THz inside plasma filaments is devised using spatio-temporal couplings. The single-shot detection configurations are theoretically described using a combination of expanded FWM models with Kostenbauder and Gaussian Q-matrices. We show that the retrieved temporal traces for THz radiation from single- and two-color laser-induced air-plasma sources match theoretical descriptions very well. High temporal resolution is shown with a detection bandwidth limited only by the spatial extent of the probe laser beam. Large detection bandwidth and temporal characterization is shown for THz radiation confined to under-dense plasma filaments induced by < 100 fs lasers below the relativistic intensity limit.
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Affiliation(s)
| | - Xi-Cheng Zhang
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA.
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9
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Denoual E, Bergé L, Davoine X, Gremillet L. Modeling terahertz emissions from energetic electrons and ions in foil targets irradiated by ultraintense femtosecond laser pulses. Phys Rev E 2023; 108:065211. [PMID: 38243518 DOI: 10.1103/physreve.108.065211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 11/20/2023] [Indexed: 01/21/2024]
Abstract
Terahertz (THz) emissions from fast electron and ion currents driven in relativistic, femtosecond laser-foil interactions are examined theoretically. We first consider the radiation from the energetic electrons exiting the backside of the target. Our kinetic model takes account of the coherent transition radiation due to these electrons crossing the plasma-vacuum interface as well as of the synchrotron radiation due to their deflection and deceleration in the sheath field they set up in vacuum. After showing that both mechanisms tend to largely compensate each other when all the electrons are pulled back into the target, we investigate the scaling of the net radiation with the sheath field strength. We then demonstrate the sensitivity of this radiation to a percent-level fraction of escaping electrons. We also study the influence of the target thickness and laser focusing. The same sheath field that confines most of the fast electrons around the target rapidly sets into motion the surface ions. We describe the THz emission from these accelerated ions and their accompanying hot electrons by means of a plasma expansion model that allows for finite foil size and multidimensional effects. Again, we explore the dependencies of this radiation mechanism on the laser-target parameters. Under conditions typical of current ultrashort laser-solid experiments, we find that the THz radiation from the expanding plasma is much less energetic-by one to three orders of magnitude-than that due to the early-time motion of the fast electrons.
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Affiliation(s)
- E Denoual
- CEA, DAM, DIF, F-91297 Arpajon, France
- Université Paris-Saclay, CEA, LMCE, F-91680 Bruyères-le-Châtel, France
| | - L Bergé
- CEA, DAM, DIF, F-91297 Arpajon, France
- Université Paris-Saclay, CEA, LMCE, F-91680 Bruyères-le-Châtel, France
- Centre des Lasers Intenses et Applications, Université de Bordeaux-CNRS-CEA, F-33405 Talence Cedex, France
| | - X Davoine
- CEA, DAM, DIF, F-91297 Arpajon, France
- Université Paris-Saclay, CEA, LMCE, F-91680 Bruyères-le-Châtel, France
| | - L Gremillet
- CEA, DAM, DIF, F-91297 Arpajon, France
- Université Paris-Saclay, CEA, LMCE, F-91680 Bruyères-le-Châtel, France
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10
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Gaida JH, Lourenço-Martins H, Yalunin SV, Feist A, Sivis M, Hohage T, García de Abajo FJ, Ropers C. Lorentz microscopy of optical fields. Nat Commun 2023; 14:6545. [PMID: 37848420 PMCID: PMC10582189 DOI: 10.1038/s41467-023-42054-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 09/25/2023] [Indexed: 10/19/2023] Open
Abstract
In electron microscopy, detailed insights into nanoscale optical properties of materials are gained by spontaneous inelastic scattering leading to electron-energy loss and cathodoluminescence. Stimulated scattering in the presence of external sample excitation allows for mode- and polarization-selective photon-induced near-field electron microscopy (PINEM). This process imprints a spatial phase profile inherited from the optical fields onto the wave function of the probing electrons. Here, we introduce Lorentz-PINEM for the full-field, non-invasive imaging of complex optical near fields at high spatial resolution. We use energy-filtered defocus phase-contrast imaging and iterative phase retrieval to reconstruct the phase distribution of interfering surface-bound modes on a plasmonic nanotip. Our approach is universally applicable to retrieve the spatially varying phase of nanoscale fields and topological modes.
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Affiliation(s)
- John H Gaida
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077, Göttingen, Germany
| | - Hugo Lourenço-Martins
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077, Göttingen, Germany
| | - Sergey V Yalunin
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077, Göttingen, Germany
| | - Armin Feist
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077, Göttingen, Germany
| | - Murat Sivis
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077, Göttingen, Germany
| | - Thorsten Hohage
- Institute of Numerical and Applied Mathematics, University of Göttingen, 37083, Göttingen, Germany
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860, Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08010, Barcelona, Spain
| | - Claus Ropers
- Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany.
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077, Göttingen, Germany.
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11
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Yannai M, Adiv Y, Dahan R, Wang K, Gorlach A, Rivera N, Fishman T, Krüger M, Kaminer I. Lossless Monochromator in an Ultrafast Electron Microscope Using Near-Field THz Radiation. PHYSICAL REVIEW LETTERS 2023; 131:145002. [PMID: 37862634 DOI: 10.1103/physrevlett.131.145002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 07/03/2023] [Accepted: 08/21/2023] [Indexed: 10/22/2023]
Abstract
The ability to form monoenergetic electron beams is vital for high-resolution electron spectroscopy and imaging. Such capabilities are commonly achieved using an electron monochromator, which energy filters a dispersed electron beam, thus reducing the electron flux to yield down to meV energy resolution. This reduction in flux hinders the use of monochromators in many applications, such as ultrafast transmission electron microscopes (UTEMs). Here, we develop and demonstrate a mechanism for electron energy monochromation that does not reduce the flux-a lossless monochromator. The mechanism is based on the interaction of free-electron pulses with single-cycle THz near fields, created by nonlinear conversion of an optical laser pulse near the electron beam path inside a UTEM. Our experiment reduces the electron energy spread by a factor of up to 2.9 without compromising the beam flux. Moreover, as the electron-THz interaction takes place over an extended region of many tens of microns in free space, the realized technique is highly robust-granting uniform monochromation over a wide area, larger than the electron beam diameter. We further demonstrate the wide tunability of our method by monochromating the electron beam at multiple primary electron energies from 60 to 200 keV, studying the effect of various electron and THz parameters on its performance. Our findings have direct applications in the fast-growing field of ultrafast electron microscopy, allowing time- and energy-resolved studies of exciton physics, phononic vibrational resonances, charge transport effects, and optical excitations in the mid IR to the far IR.
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Affiliation(s)
- Michael Yannai
- Faculty of Electrical & Computer Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Yuval Adiv
- Faculty of Electrical & Computer Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Raphael Dahan
- Faculty of Electrical & Computer Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Kangpeng Wang
- Faculty of Electrical & Computer Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201815, China
| | - Alexey Gorlach
- Faculty of Electrical & Computer Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Nicholas Rivera
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Tal Fishman
- Faculty of Electrical & Computer Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Michael Krüger
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Department of Physics, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Ido Kaminer
- Faculty of Electrical & Computer Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
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12
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Rohrbach D, Kang BJ, Zyaee E, Feurer T. Wideband dispersion-free THz waveguide platform. Sci Rep 2023; 13:15228. [PMID: 37709825 PMCID: PMC10502044 DOI: 10.1038/s41598-023-41843-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 08/31/2023] [Indexed: 09/16/2023] Open
Abstract
We present a versatile THz waveguide platform for frequencies between 0.1 THz and 1.5 THz, designed to exhibit vacuum-like dispersion and electric as well as magnetic field enhancement. While linear THz spectroscopy benefits from the extended interaction length in combination with moderate losses, nonlinear THz spectroscopy profits from the field enhancement and zero dispersion, with the associated reshaping-free propagation of broadband single- to few-cycle THz pulses. Moreover, the vacuum-like dispersion allows for velocity matching in mixed THz and visible to infrared pump-probe experiments. The platform is based on the motif of a metallic double ridged waveguide. We experimentally characterize essential waveguide properties, for instance, propagation and bending losses, but also demonstrate a junction and an interferometer, essentially because those elements are prerequisites for THz waveform synthesis, and hence, for coherently controlled linear and nonlinear THz interactions.
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Affiliation(s)
- David Rohrbach
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland.
| | - Bong Joo Kang
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Elnaz Zyaee
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Thomas Feurer
- Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
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13
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Margenberg N, Kärtner FX, Bause M. Accurate simulation of THz generation with finite-element time domain methods. OPTICS EXPRESS 2023; 31:25915-25932. [PMID: 37710465 DOI: 10.1364/oe.480793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/26/2023] [Indexed: 09/16/2023]
Abstract
We investigate the accurate full broadband simulation of complex nonlinear optical processes. A mathematical model and numerical simulation techniques in the time domain are developed to simulate complex nonlinear optical processes without the usual used slowly varying envelope approximation. We illustrate the accuracy by numerical simulations. Furthermore, they are used to elucidate THz generation in periodically poled Lithium Niobate (PPLN) including optical harmonic generation.
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14
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Iwase H, Ohno S. Direct generation of a terahertz vector beam from a ZnTe crystal excited by a focused circular polarized pulse. OPTICS EXPRESS 2023; 31:26923-26934. [PMID: 37710541 DOI: 10.1364/oe.494366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 07/19/2023] [Indexed: 09/16/2023]
Abstract
A vector beam is a type of topological beam in which the polarization direction of light rotates around a singularity on the wavefront. This paper proposes a method to generate a vector beam by tightly focusing a pump beam in the crystalline direction such that the second-order nonlinear optical effect is forbidden. The directional dependence of the effective nonlinearity in zincblende crystals, such as ZnTe, was analytically investigated. Two types of nonlinear polarization singularities were found in [111] and [100] directions. Their polarization topological charge ℓ was +1 and -1, respectively. To experimentally demonstrate the proposed method, a (111) cut ZnTe crystal was selected as the nonlinear crystal. The polarization state of the generated terahertz (THz) beams was measured with a custom-built THz spectroscopic polarization imaging system. Radially polarized distributions were observed within the entire generated spectral region. Such a broadband feature of the generated vector beam is likely due to the topological nature of the focused pump beam, where the wavevectors are winding once about the optical axis. This simple method for generating THz vector beams will accelerate its applications.
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15
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D'Mello Y, Dahan R, Bernal S, Shi X, Kaminer I, Plant DV. Efficient coupling between free electrons and the supermode of a silicon slot waveguide. OPTICS EXPRESS 2023; 31:19443-19452. [PMID: 37381359 DOI: 10.1364/oe.491452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/12/2023] [Indexed: 06/30/2023]
Abstract
Laser light can modulate the kinetic energy spectrum of free electrons and induce extremely high acceleration gradients, which are instrumental to electron microscopy and electron acceleration, respectively. We present a design scheme for a silicon photonic slot waveguide which hosts a supermode to interact with free electrons. The efficiency of this interaction relies on the coupling strength per photon along the interaction length. We predict an optimum value of 0.4266, resulting in the maximum energy gain of 28.27 keV for an optical pulse energy of only 0.22 nJ and duration 1 ps. The acceleration gradient is 1.05 GeV/m, which is lower than the maximum imposed by the damage threshold of Si waveguides. Our scheme shows how the coupling efficiency and energy gain can be maximized without maximizing the acceleration gradient. It highlights the potential of silicon photonics technology in hosting electron-photon interactions with direct applications in free-electron acceleration, radiation sources, and quantum information science.
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16
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Boland JL, Damry DA, Xia CQ, Schönherr P, Prabhakaran D, Herz LM, Hesjedal T, Johnston MB. Narrowband, Angle-Tunable, Helicity-Dependent Terahertz Emission from Nanowires of the Topological Dirac Semimetal Cd 3As 2. ACS PHOTONICS 2023; 10:1473-1484. [PMID: 37215322 PMCID: PMC10197169 DOI: 10.1021/acsphotonics.3c00068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Indexed: 05/24/2023]
Abstract
All-optical control of terahertz pulses is essential for the development of optoelectronic devices for next-generation quantum technologies. Despite substantial research in THz generation methods, polarization control remains difficult. Here, we demonstrate that by exploiting band structure topology, both helicity-dependent and helicity-independent THz emission can be generated from nanowires of the topological Dirac semimetal Cd3As2. We show that narrowband THz pulses can be generated at oblique incidence by driving the system with optical (1.55 eV) pulses with circular polarization. Varying the incident angle also provides control of the peak emission frequency, with peak frequencies spanning 0.21-1.40 THz as the angle is tuned from 15 to 45°. We therefore present Cd3As2 nanowires as a promising novel material platform for controllable terahertz emission.
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Affiliation(s)
- Jessica L. Boland
- Photon
Science Institute, Department of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL, U.K.
| | - Djamshid A. Damry
- Photon
Science Institute, Department of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL, U.K.
| | - Chelsea Q. Xia
- Department
of Physics, University of Oxford, Clarendon
Laboratory, Parks Road, Oxford OX1
3PU, U.K.
| | - Piet Schönherr
- Department
of Physics, University of Oxford, Clarendon
Laboratory, Parks Road, Oxford OX1
3PU, U.K.
| | - Dharmalingam Prabhakaran
- Department
of Physics, University of Oxford, Clarendon
Laboratory, Parks Road, Oxford OX1
3PU, U.K.
| | - Laura M. Herz
- Department
of Physics, University of Oxford, Clarendon
Laboratory, Parks Road, Oxford OX1
3PU, U.K.
| | - Thorsten Hesjedal
- Department
of Physics, University of Oxford, Clarendon
Laboratory, Parks Road, Oxford OX1
3PU, U.K.
| | - Michael B. Johnston
- Department
of Physics, University of Oxford, Clarendon
Laboratory, Parks Road, Oxford OX1
3PU, U.K.
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17
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Zhang L, Liu W, Xu H, Jia Q, Lu Y. Cascade bunch focusing on chip using terahertz pulses to drive prism arrays. OPTICS LETTERS 2023; 48:2704-2707. [PMID: 37186745 DOI: 10.1364/ol.491679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The dielectric laser accelerator (DLA) is a promising candidate for next-generation table-top and even on-chip particle accelerators. Long-range focusing of a tiny-size electron bunch on chip is crucial for the practical applications of DLA, which has been a challenge. Here we propose a bunch focusing scheme, which uses a pair of readily available few-cycle terahertz (THz) pulses to drive an array of millimeter-scale prisms via the inverse Cherenkov effect. The THz pulses are reflected and refracted multiple times through the prism arrays, synchronizing with and periodically focusing the electron bunch along the bunch channel. Cascade bunch-focusing is realized by making the electromagnetic field phase experienced by electrons in each stage of the array, that is, the synchronous phase, in the focusing phase region. The focusing strength can be adjusted via changing the synchronous phase and THz field intensity, optimization of which will sustain the stable bunch transportation in a tiny-size bunch channel on chip. This bunch-focusing scheme sets a base for developing a long-acceleration-range and high-gain DLA.
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18
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Rust C, Schill E, Garrity O, Spari M, Li H, Bacher A, Guttmann M, Reich S, Flavel BS. Radial Alignment of Carbon Nanotubes via Dead-End Filtration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2207684. [PMID: 36775908 DOI: 10.1002/smll.202207684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/25/2023] [Indexed: 05/11/2023]
Abstract
Dead-end filtration is a facile method to globally align single wall carbon nanotubes (SWCNTs) in large area films with a 2D order parameter, S2D , approaching unity. Uniaxial alignment has been achieved using pristine and hot-embossed membranes but more sophisticated geometries have yet to be investigated. In this work, three different patterns with radial symmetry and an area of 3.8 cm2 are created. Two of these patterns are replicated by the filtered SWCNTs and S2D values of ≈0.85 are obtained. Each of the radially aligned SWCNT films is characterized by scanning cross-polarized microscopy in reflectance and laser imaging in transmittance with linear, radial, and azimuthal polarized light fields. The former is used to define a novel indicator akin to the 2D order parameter using Malu's law, yielding 0.82 for the respective film. The films are then transferred to a flexible printed circuit board and terminal two-probe electrical measurements are conducted to explore the potential of those new alignment geometries.
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Affiliation(s)
- Christian Rust
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287, Darmstadt, Germany
| | - Elias Schill
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Oisín Garrity
- Institute of Experimental Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Manuel Spari
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Han Li
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Andreas Bacher
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Markus Guttmann
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Stephanie Reich
- Institute of Experimental Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Benjamin S Flavel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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19
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Kumar M, Song HS, Lee J, Park D, Suk H, Hur MS. Intense multicycle THz pulse generation from laser-produced nanoplasmas. Sci Rep 2023; 13:4233. [PMID: 36918732 PMCID: PMC10015041 DOI: 10.1038/s41598-023-31427-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/11/2023] [Indexed: 03/16/2023] Open
Abstract
We present a novel scheme to obtain robust, narrowband, and tunable THz emission using a nano-dimensional overdense plasma target, irradiated by two counter-propagating detuned laser pulses. So far, no narrowband THz sources with a field strength of GV/m-level have been reported from laser-solid interaction (mostly half-or single-cycle THz pulses with only broadband frequency spectrum). From two- and three-dimensional particle-in-cell simulations, we find that the strong plasma current generated by the beat ponderomotive force in the colliding region, produces beat-frequency radiation in the THz range. Here we report intense THz pulses [Formula: see text]THz) with an unprecedentedly high peak field strength of 11.9 GV/m and spectral width [Formula: see text], which leads to a regime of an extremely bright narrowband THz source of TW/cm[Formula: see text], suitable for various ambitious applications.
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Affiliation(s)
- Manoj Kumar
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Hyung Seon Song
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Jaeho Lee
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Dohyun Park
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Hyyong Suk
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju, 61005, Republic of Korea
| | - Min Sup Hur
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea.
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20
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Kong H, Chung M, Doran DS, Ha G, Kim SH, Kim JH, Liu W, Lu X, Power J, Seok JM, Shin S, Shao J, Whiteford C, Wisniewski E. Fabrication of THz corrugated wakefield structure and its high power test. Sci Rep 2023; 13:3207. [PMID: 36828881 PMCID: PMC9958108 DOI: 10.1038/s41598-023-29997-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 02/14/2023] [Indexed: 02/26/2023] Open
Abstract
We present overall process for developing terahertz (THz) corrugated structure and its beam-based measurement results. 0.2-THz corrugated structures were fabricated by die stamping method as the first step demonstration towards GW THz radiation source and GV/m THz wakefield accelerator. 150-[Formula: see text]m thick disks were produced from an OFHC (C10100) foil by stamping. Two types of disks were stacked alternately to form 46 mm structure with [Formula: see text] 170 corrugations. Custom assembly was designed to provide diffusion bonding with a high precision alignment of disks. The compliance of the fabricated structure have been verified through beam-based wakefield measurement at Argonne Wakefield Accelerator Facility. Both measured longitudinal and transverse wakefield showed good agreement with simulated wakefields. Measured peak gradients, 9.4 MV/m/nC for a long single bunch and 35.4 MV/m/nC for a four bunch trains, showed good agreement with the simulation.
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Affiliation(s)
- H Kong
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyungbuk, 37673, Korea.,Department of Physics, Kyungpook National University, Daegu, 41566, Korea
| | - M Chung
- Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea
| | - D S Doran
- Argonne National Laboratory, Argonne, IL, 60439, USA
| | - G Ha
- Argonne National Laboratory, Argonne, IL, 60439, USA.
| | - S-H Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyungbuk, 37673, Korea
| | - J-H Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyungbuk, 37673, Korea
| | - W Liu
- Argonne National Laboratory, Argonne, IL, 60439, USA
| | - X Lu
- Argonne National Laboratory, Argonne, IL, 60439, USA.,Northern Illinois University, Dekalb, IL, 60115, USA
| | - J Power
- Argonne National Laboratory, Argonne, IL, 60439, USA
| | - J-M Seok
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyungbuk, 37673, Korea.,Argonne National Laboratory, Argonne, IL, 60439, USA
| | - S Shin
- Department of Accelerator Science, Korea University, Sejong, 30019, Korea.
| | - J Shao
- Argonne National Laboratory, Argonne, IL, 60439, USA
| | - C Whiteford
- Argonne National Laboratory, Argonne, IL, 60439, USA
| | - E Wisniewski
- Argonne National Laboratory, Argonne, IL, 60439, USA
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21
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Pak T, Rezaei-Pandari M, Kim SB, Lee G, Wi DH, Hojbota CI, Mirzaie M, Kim H, Sung JH, Lee SK, Kang C, Kim KY. Multi-millijoule terahertz emission from laser-wakefield-accelerated electrons. LIGHT, SCIENCE & APPLICATIONS 2023; 12:37. [PMID: 36740599 PMCID: PMC9899771 DOI: 10.1038/s41377-022-01068-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 12/11/2022] [Accepted: 12/28/2022] [Indexed: 06/18/2023]
Abstract
High-power terahertz radiation was observed to be emitted from a gas jet irradiated by 100-terawatt-class laser pulses in the laser-wakefield acceleration of electrons. The emitted terahertz radiation was characterized in terms of its spectrum, polarization, and energy dependence on the accompanying electron bunch energy and charge under various gas target conditions. With a nitrogen target, more than 4 mJ of energy was produced at <10 THz with a laser-to-terahertz conversion efficiency of ~0.15%. Such strong terahertz radiation is hypothesized to be produced from plasma electrons accelerated by the ponderomotive force of the laser and the plasma wakefields on the time scale of the laser pulse duration and plasma period. This model is examined with analytic calculations and particle-in-cell simulations to better understand the generation mechanism of high-energy terahertz radiation in laser-wakefield acceleration.
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Affiliation(s)
- Taegyu Pak
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Korea
| | - Mohammad Rezaei-Pandari
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
| | - Sang Beom Kim
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Korea
| | - Geonwoo Lee
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Korea
| | - Dae Hee Wi
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Korea
| | - Calin Ioan Hojbota
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Mohammad Mirzaie
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Hyeongmun Kim
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
| | - Jae Hee Sung
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
| | - Seong Ku Lee
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
| | - Chul Kang
- Advanced Photonics Research Institute, GIST, Gwangju, 61005, Korea
| | - Ki-Yong Kim
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea.
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Korea.
- Institute for Research in Electronics and Applied Physics and Department of Physics, University of Maryland, College Park, Maryland, 20742, USA.
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22
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Mosley CDW, Lake DS, Graham DM, Jamison SP, Appleby RB, Burt G, Hibberd MT. Large-area periodically-poled lithium niobate wafer stacks optimized for high-energy narrowband terahertz generation. OPTICS EXPRESS 2023; 31:4041-4054. [PMID: 36785381 DOI: 10.1364/oe.475604] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 12/06/2022] [Indexed: 06/18/2023]
Abstract
Periodically-poled lithium niobate (PPLN) sources consisting of custom-built stacks of large-area wafers provide a unique opportunity to systematically study the multi-cycle terahertz (THz) generation mechanism as they are assembled layer-by-layer. Here we investigate and optimize the THz emission from PPLN wafer stacks as a function of wafer number, pump fluence, pulse duration and chirp, wafer separation, and pump focusing. Using 135 µm-thick, 2"-diameter wafers we generate high-energy, narrowband THz pulses with central frequencies up to 0.39 THz, directly suitable for THz-driven particle acceleration applications. We explore the multi-cycle pulse build-up with increasing wafer numbers using electro-optic sampling measurements, achieving THz conversion efficiencies up to 0.17%, while demonstrating unique control over the pulse length and bandwidth these sources offer. Guided by simulations, observed frequency-dependence on both stack-mounting and pump focusing conditions have been attributed to inter-wafer etalon and Gouy phase-shifts respectively, revealing subtle features that are critical to the understanding and performance of PPLN wafer-stack sources for optimal narrowband THz generation.
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23
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Widarsson M, Brunzell M, Laurell F, Pasiskevicius V. Self-mode-locking through intra-cavity sum-frequency generation. OPTICS EXPRESS 2022; 30:40906-40915. [PMID: 36299015 DOI: 10.1364/oe.471431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
A new technique for mode-locking is demonstrated based on two lasers sharing one leg for sum-frequency generation. When the two lasers had equal round trip time one will produce bright pulses and the other dark pulses. Both lasers used Nd:YVO4 as the gain material, but operated at different wavelengths, namely 1064 nm and 1342 nm. In the present configuration, sub-250 ps pulses were generated at a repetition rate of 276 MHz with an output power of 70 mW. With appropriate choice of round trip loss at the two wavelengths it was possible to choose which laser was generating the bright pulses.
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24
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Kuratov AS, Brantov AV, Kovalev VF, Bychenkov VY. Powerful laser-produced quasi-half-cycle THz pulses. Phys Rev E 2022; 106:035201. [PMID: 36266787 DOI: 10.1103/physreve.106.035201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/16/2022] [Indexed: 06/16/2023]
Abstract
The Maxwell equations-based 3D-analytical solution for the terahertz (THz) half-cycle electromagnetic wave transition radiation pulse has been found. This solution describes generation and propagation of transition radiation into free space from laser-produced relativistic electron bunch which crosses a target-vacuum interface as a result of ultrashort laser pulse interaction with a thin high-conductivity target. The analytical solution found complements the theory of laser initiated transition radiation. It describes the THz wave half-cycle pulse at the arbitrary distance from a target surface including near-field zone rather than its standard far-field characterization. The analytical research has also been supplemented with the 3D simulations using the finite-difference time-domain method, which makes it possible for description of much wider spatial domain as compared to that from the particle-in-cell approach. The presented result sheds light fundamentally on the interference of the electron bunch field and the generated THz field of broadband transition radiation from laser-plasma interaction. The latter is studied for a long time in the experiments with solid density plasma and the theory developed may inspire to targeted measurements and investigations of unique super intense half-cycle THz radiation waves near the laser target.
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Affiliation(s)
- A S Kuratov
- P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii Prospect 53, Moscow 119991, Russia
- Center for Fundamental and Applied Research, Dukhov Research Institute of Automatics (VNIIA), Moscow 127055, Russia
| | - A V Brantov
- P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii Prospect 53, Moscow 119991, Russia
- Center for Fundamental and Applied Research, Dukhov Research Institute of Automatics (VNIIA), Moscow 127055, Russia
| | - V F Kovalev
- P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii Prospect 53, Moscow 119991, Russia
- Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow 125047, Russia
| | - V Yu Bychenkov
- P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii Prospect 53, Moscow 119991, Russia
- Center for Fundamental and Applied Research, Dukhov Research Institute of Automatics (VNIIA), Moscow 127055, Russia
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25
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Tibai Z, Turnár S, Tóth G, Hebling J, Jolly SW. Spatiotemporal modeling of direct acceleration with high-field terahertz pulses. OPTICS EXPRESS 2022; 30:32861-32870. [PMID: 36242339 DOI: 10.1364/oe.461421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 06/24/2022] [Indexed: 06/16/2023]
Abstract
We present an improved model for electron acceleration in vacuum with high-energy THz pulses that includes spatiotemporal effects. In our calculations, we examined the acceleration with 300 GHz and 3.0 THz central frequency THz pulses with properties corresponding to common sources, and compared the Gaussian and Poisson spectral amplitudes and the associated time profiles of the electric fields. Our calculation takes into account both the longitudinal field and the spatio-spectral evolution around the focus. These aspects of the model are necessary due to the tight focusing and the duration towards a single-cycle of the THz pulses, respectively. The carrier-to-envelope phase (CEP) and the tilting angle of the coincident few- or single-cycle THz pulses must be tuned in all cases in order to optimize the acceleration scheme. We reveal additionally that electron beams with different final energies and different divergences can be generated based on simulated THz pulses having different Porras factors, describing the frequency dependence of the spatiotemporal amplitude profile, which may depend strongly on the method used to generate the single-cycle THz pulses.
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26
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Turnár S, Krizsán G, Hebling J, Tibai Z. Waveguide structure based electron acceleration using terahertz pulses. OPTICS EXPRESS 2022; 30:27602-27608. [PMID: 36236928 DOI: 10.1364/oe.459282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/24/2022] [Indexed: 06/16/2023]
Abstract
We have developed a waveguide structure for electron acceleration using a few µJ energy THz pulse. The metallic device focuses the incoming linearly polarized nearly single-cycle THz pulse, hence increasing the peak electric field strength. We experimentally verified the gain and the temporal profile of the electric field in the structure using electro-optic sampling technique. The acceleration of the electron bunch from rest up to 8 keV was predicted using single-cycle THz pulses with µJ-energy level.
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27
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Han B, Chen Y, Xia T, Wang L, Wang C, Sheng Z. Measurement and Control of Radially Polarized THz Radiation from DC-Biased Laser Plasma Filaments in Air. SENSORS (BASEL, SWITZERLAND) 2022; 22:5231. [PMID: 35890911 PMCID: PMC9322885 DOI: 10.3390/s22145231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/26/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Detection and manipulation of radially polarized terahertz (THz) radiation is essential for many applications. A new measurement scheme is proposed for the diagnosis of radially polarized THz radiation from a longitudinal dc-biased plasma filament, by introducing a movable metal mask. The amplitude and spectrum of the radially polarized THz beam was measured with a <110>-cut ZnTe crystal, where the THz beam pattern was modulated by the mask. Based on this measurement scheme, it was demonstrated that the amplitude and spectrum of the radially polarized THz radiation from the longitudinal dc-biased filament could be manipulated by controlling the strength and the location of the dc-biased field.
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Affiliation(s)
- Bonan Han
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China; (B.H.); (T.X.); (L.W.); (C.W.); (Z.S.)
- Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yanping Chen
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China; (B.H.); (T.X.); (L.W.); (C.W.); (Z.S.)
- Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tianhao Xia
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China; (B.H.); (T.X.); (L.W.); (C.W.); (Z.S.)
- Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Linzheng Wang
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China; (B.H.); (T.X.); (L.W.); (C.W.); (Z.S.)
- Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chen Wang
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China; (B.H.); (T.X.); (L.W.); (C.W.); (Z.S.)
- Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhengming Sheng
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China; (B.H.); (T.X.); (L.W.); (C.W.); (Z.S.)
- Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
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28
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Lei HY, Sun FZ, Wang TZ, Chen H, Wang D, Wei YY, Ma JL, Liao GQ, Li YT. Highly efficient generation of GV/m-level terahertz pulses from intense femtosecond laser-foil interactions. iScience 2022; 25:104336. [PMID: 35602940 PMCID: PMC9118729 DOI: 10.1016/j.isci.2022.104336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/06/2022] [Accepted: 04/27/2022] [Indexed: 11/05/2022] Open
Abstract
The terahertz radiation from ultraintense laser-produced plasmas has aroused increasing attention recently as a promising approach toward strong terahertz sources. Here, we present the highly efficient production of millijoule-level terahertz pulses, from the rear side of a metal foil irradiated by a 10-TW femtosecond laser pulse. By characterizing the terahertz and electron emission in combination with particle-in-cell simulations, the physical reasons behind the efficient terahertz generation are discussed. The resulting focused terahertz electric field strength reaches over 2 GV/m, which is justified by experiments on terahertz strong-field-driven nonlinearity in semiconductors. Ultraintense laser-foil interactions generate a 2.1-mJ strong terahertz pulse Nearly 1% generation efficiency originates from optimized laser-plasma conditions 2-GV/m high THz fields induce absorption bleaching and impact ionization
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Affiliation(s)
- Hong-Yi Lei
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fang-Zheng Sun
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tian-Ze Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hao Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dan Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan-Yu Wei
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing-Long Ma
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Guo-Qian Liao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan 523808, Guangdong, China
| | - Yu-Tong Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.,Songshan Lake Materials Laboratory, Dongguan 523808, Guangdong, China.,Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
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29
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Olgun HT, Tian W, Cirmi G, Ravi K, Rentschler C, Çankaya H, Pergament M, Hemmer M, Hua Y, Schimpf DN, Matlis NH, Kärtner FX. Highly efficient generation of narrowband terahertz radiation driven by a two-spectral-line laser in PPLN. OPTICS LETTERS 2022; 47:2374-2377. [PMID: 35561354 DOI: 10.1364/ol.448457] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/28/2022] [Indexed: 06/15/2023]
Abstract
We demonstrate record ∼0.9% efficiencies for optical conversion to narrowband (<1% relative bandwidth) terahertz (THz) radiation by strongly cascaded difference frequency generation. These results are achieved using a novel, to the best of our knowledge, laser source, customized for high efficiencies, with two narrow spectral lines of variable separation and pulse duration (≥250 ps). THz radiation generation in 5% MgO-doped periodically poled lithium niobate (PPLN) crystals of varying poling period was explored at cryogenic and room temperature operation as well as with different crystal lengths. This work addresses an increasing demand for high-field THz radiation pulses which has, up to now, been largely limited by low optical-to-THz radiation conversion efficiencies.
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30
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Li P, Liu S, Chen X, Geng C, Wu X. Spintronic terahertz emission with manipulated polarization (STEMP). FRONTIERS OF OPTOELECTRONICS 2022; 15:12. [PMID: 36637604 PMCID: PMC9756272 DOI: 10.1007/s12200-022-00011-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 01/11/2022] [Indexed: 06/17/2023]
Abstract
Highly efficient generation and arbitrary manipulation of spin-polarized terahertz (THz) radiation will enable chiral lightwave driven quantum nonequilibrium state regulation, induce new electronic structures, consequently provide a powerful experimental tool for investigation of nonlinear THz optics and extreme THz science and applications. THz circular dichromic spectroscopy, ultrafast electron bunch manipulation, as well as THz imaging, sensing, and telecommunication, also need chiral THz waves. Here we review optical generation of circularly-polarized THz radiation but focus on recently emerged polarization tunable spintronic THz emission techniques, which possess many advantages of ultra-broadband, high efficiency, low cost, easy for integration and so on. We believe that chiral THz sources based on the combination of electron spin, ultrafast optical techniques and material structure engineering will accelerate the development of THz science and applications.
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Affiliation(s)
- Peiyan Li
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
| | - Shaojie Liu
- School of Cyber Science and Technology, Beihang University, Beijing, 100191, China
| | - Xinhou Chen
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
| | - Chunyan Geng
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China
| | - Xiaojun Wu
- School of Electronic and Information Engineering, Beihang University, Beijing, 100191, China.
- School of Cyber Science and Technology, Beihang University, Beijing, 100191, China.
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China.
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31
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Hermann B, Haeusler U, Yadav G, Kirchner A, Feurer T, Welsch C, Hommelhoff P, Ischebeck R. Inverse-Designed Narrowband THz Radiator for Ultrarelativistic Electrons. ACS PHOTONICS 2022; 9:1143-1149. [PMID: 35480494 PMCID: PMC9026277 DOI: 10.1021/acsphotonics.1c01932] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Indexed: 06/14/2023]
Abstract
THz radiation finds various applications in science and technology. Pump-probe experiments at free-electron lasers typically rely on THz radiation generated by optical rectification of ultrafast laser pulses in electro-optic crystals. A compact and cost-efficient alternative is offered by the Smith-Purcell effect: a charged particle beam passes a periodic structure and generates synchronous radiation. Here, we employ the technique of photonic inverse design to optimize a structure for Smith-Purcell radiation at a single wavelength from ultrarelativistic electrons. The resulting design is highly resonant and emits narrowbandly. Experiments with a 3D-printed model for a wavelength of 900 μm show coherent enhancement. The versatility of inverse design offers a simple adaption of the structure to other electron energies or radiation wavelengths. This approach could advance beam-based THz generation for a wide range of applications.
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Affiliation(s)
- Benedikt Hermann
- Paul
Scherrer Institut, 5232 Villigen, PSI, Switzerland
- Institute
of Applied Physics, University of Bern, 3012 Bern, Switzerland
- Galatea
Laboratory, Ecole Polytechnique Fédérale
de Lausanne (EPFL), 2000 Neuchâtel, Switzerland
| | - Urs Haeusler
- Department
Physik, Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
- Cavendish
Laboratory, University of Cambridge, Cambridge, CB3 0HE, United Kingdom
| | - Gyanendra Yadav
- Department
of Physics, University of Liverpool, Liverpool, L69 7ZE, United Kingdom
- Cockcroft
Institute, Warrington, WA4 4AD, United Kingdom
| | - Adrian Kirchner
- Department
Physik, Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Thomas Feurer
- Institute
of Applied Physics, University of Bern, 3012 Bern, Switzerland
| | - Carsten Welsch
- Department
of Physics, University of Liverpool, Liverpool, L69 7ZE, United Kingdom
- Cockcroft
Institute, Warrington, WA4 4AD, United Kingdom
| | - Peter Hommelhoff
- Department
Physik, Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
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32
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Mine S, Kawase K, Murate K. Noise-free terahertz-wave parametric generator. OPTICS LETTERS 2022; 47:1113-1116. [PMID: 35230304 DOI: 10.1364/ol.448636] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
We achieved noise-free terahertz (THz)-wave output from an injection-seeded THz-wave parametric generator (is-TPG) employing high-power injection seeding. A conventional is-TPG uses a weak continuous-wave (CW) seed beam. The position in which broadband noise is generated (via spontaneous parametric down-conversion) and the position of the THz signal overlap. Thus, the output features broadband TPG noise, reducing the signal-to-noise ratio. To solve this problem, we shifted the position in which the THz signal is generated to the front of the crystal; we separated the signal from broadband TPG noise using a high-powered, pulsed seed beam that was 107-fold more powerful than the CW seed beam. Thus, we extracted only the THz signal; we achieved a noise-free is-TPG. This system features a signal-to-noise ratio of 95 dB, approximately 40 dB better than the signal-to-noise ratio of the conventional system.
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33
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Compressed sensing in fluorescence microscopy. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 168:66-80. [PMID: 34153330 DOI: 10.1016/j.pbiomolbio.2021.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/29/2021] [Accepted: 06/07/2021] [Indexed: 12/30/2022]
Abstract
Compressed sensing (CS) is a signal processing approach that solves ill-posed inverse problems, from under-sampled data with respect to the Nyquist criterium. CS exploits sparsity constraints based on the knowledge of prior information, relative to the structure of the object in the spatial or other domains. It is commonly used in image and video compression as well as in scientific and medical applications, including computed tomography and magnetic resonance imaging. In the field of fluorescence microscopy, it has been demonstrated to be valuable for fast and high-resolution imaging, from single-molecule localization, super-resolution to light-sheet microscopy. Furthermore, CS has found remarkable applications in the field of mesoscopic imaging, facilitating the study of small animals' organs and entire organisms. This review article illustrates the working principles of CS, its implementations in optical imaging and discusses several relevant uses of CS in the field of fluorescence imaging from super-resolution microscopy to mesoscopy.
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34
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Rahman S, Torres JF, Khan AR, Lu Y. Recent Developments in van der Waals Antiferromagnetic 2D Materials: Synthesis, Characterization, and Device Implementation. ACS NANO 2021; 15:17175-17213. [PMID: 34779616 DOI: 10.1021/acsnano.1c06864] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Magnetism in two dimensions is one of the most intriguing and alluring phenomena in condensed matter physics. Atomically thin 2D materials have emerged as a promising platform for exploring magnetic properties, leading to the development of essential technologies such as supercomputing and data storage. Arising from spin and charge dynamics in elementary particles, magnetism has also unraveled promising advances in spintronic devices and spin-dependent optoelectronics and photonics. Recently, antiferromagnetism in 2D materials has received extensive attention, leading to significant advances in their understanding and emerging applications; such materials have zero net magnetic moment yet are internally magnetic. Several theoretical and experimental approaches have been proposed to probe, characterize, and modulate the magnetic states efficiently in such systems. This Review presents the latest developments and current status for tuning the magnetic properties in distinct 2D van der Waals antiferromagnets. Various state-of-the-art optical techniques deployed to investigate magnetic textures and dynamics are discussed. Furthermore, device concepts based on antiferromagnetic spintronics are scrutinized. We conclude with remarks on related challenges and technological outlook in this rapidly expanding field.
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Affiliation(s)
- Sharidya Rahman
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Juan F Torres
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Ahmed Raza Khan
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Yuerui Lu
- School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia
- ARC Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Acton, ACT 2601, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), ANU node, Canberra, ACT 2601, Australia
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35
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Hassani M, Jahangiri F. Tuning single-walled aligned carbon nanotubes for optimal terahertz pulse generation through optical rectification of ultrashort laser pulses. OPTICS EXPRESS 2021; 29:38359-38375. [PMID: 34808890 DOI: 10.1364/oe.442168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Terahertz radiation by optical rectification in single-walled highly aligned chiral carbon nanotubes (SWCNTs) irradiated by ultrashort laser pulses is comprehensively studied. We take into account the structural properties of SWCNTs, including the filling factor, alignment, and chirality, as well as the laser pulse parameters including the pulse duration and the wavelength. The second-order nonlinear susceptibility tensor and, consequently, polarization responsible for optical rectification in SWCNTs are derived based on symmetrical features.The effective dielectric constants of SWCNTs are also extracted using the effective medium approximation. Then, the propagation effects in terms of the group velocity dispersion and absorption at both pump and terahertz pulse frequency regions are investigated. By adjusting the laser and the structure effective parameters among those practically feasible, minimum velocity mismatch required for optimum optical rectification and coherent amplification at terahertz frequencies in SWCNTs are introduced. Comparing the electric field waveform and the spectrum of the generated terahertz pulses under various conditions reveals that SWCNTs with higher alignment and lower filling factor at chirality (6,4) irradiated by an ultrashort laser pulse with the wavelength of 1550 nm could provide the conditions for maximum terahertz radiation generation.
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36
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Tan YJ, Pitchappa P, Wang N, Singh R, Wong LJ. Space-Time Wave Packets from Smith-Purcell Radiation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100925. [PMID: 34658164 PMCID: PMC8596120 DOI: 10.1002/advs.202100925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Space-time wave packets are electromagnetic waves with strong correlations between their spatial and temporal degrees of freedom. These wave packets have gained much attention for fundamental properties like propagation invariance and user-designed group velocities, and for potential applications like optical microscopy, micromanipulation, and laser micromachining. Here, free-electron radiation is presented as a natural and versatile source of space-time wave packets that are ultra-broadband and highly tunable in frequency. For instance, ab initio theory and numerical simulations show that the intensity profile of space-time wave packets from Smith-Purcell radiation can be directly tailored through the grating properties, as well as the velocity and shape of the electron bunches. The result of this work indicates a viable way of generating space-time wave packets at exotic frequencies such as the terahertz and X-ray regimes, potentially paving the way toward new methods of shaping electromagnetic wave packets through free-electron radiation.
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Affiliation(s)
- Yi Ji Tan
- Institute of MicroelectronicsAgency for Science, Technology and Research (A*STAR)2 Fusionopolis WaySingapore138634Singapore
- School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang LinkSingapore637371Singapore
| | - Prakash Pitchappa
- Institute of MicroelectronicsAgency for Science, Technology and Research (A*STAR)2 Fusionopolis WaySingapore138634Singapore
| | - Nan Wang
- Institute of MicroelectronicsAgency for Science, Technology and Research (A*STAR)2 Fusionopolis WaySingapore138634Singapore
| | - Ranjan Singh
- School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang LinkSingapore637371Singapore
| | - Liang Jie Wong
- School of Electrical and Electronic EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
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37
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Liu W, Sun L, Yu Z, Liu Y, Jia Q, Sun B, Xu H. THz-driven dielectric particle accelerator on chip. OPTICS LETTERS 2021; 46:4398-4401. [PMID: 34470025 DOI: 10.1364/ol.430451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Recently, terahertz (THz)-driven particle accelerators have drawn increasing attention. The development of high-energy-gain THz accelerators on chip has been a challenge. Here we propose a concept of an on-chip THz-driven particle accelerator that uses few-cycle THz pulses to drive dielectric prisms. It avoids the serious waveguide dispersion of previous THz linacs based on dielectric lined waveguides and enhances the electron-energy gain. In addition, we propose to use prism stacks to overcome the asynchronization effect when accelerating low-energy particles, by which a longer acceleration length with even higher energy gain can be realized. Compared with the available on-chip dielectric laser accelerators, the proposed scheme avoids serious dielectric dispersion and enhances accelerated bunch charge. Hence, it promises an attractive particle accelerator on chip.
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38
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Rohrbach D, Kang BJ, Feurer T. 3D-printed THz wave- and phaseplates. OPTICS EXPRESS 2021; 29:27160-27170. [PMID: 34615137 DOI: 10.1364/oe.433881] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Three-dimensional printing based on fused deposition modeling has been shown to provide a cost-efficient and time-saving tool for fabricating a variety of THz optics for a frequency range of <0.2 THz. By using a broadband THz source, with a useful spectral range from 0.08 THz to 1.5 THz, we show that 3D-printed waveplates operate well up to 0.6 THz and have bandwidths similar to commercial products. Specifically, we investigate quarter- and half-waveplates, q-plates, and spiral phaseplates. We demonstrate a route to achieve broadband performance, so that 3D-printed waveplates can also be used with broadband, few-cycle THz pulses, for instance, in nonlinear THz spectroscopy or other THz high field applications.
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39
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Tang H, Zhao L, Zhu P, Zou X, Qi J, Cheng Y, Qiu J, Hu X, Song W, Xiang D, Zhang J. Stable and Scalable Multistage Terahertz-Driven Particle Accelerator. PHYSICAL REVIEW LETTERS 2021; 127:074801. [PMID: 34459641 DOI: 10.1103/physrevlett.127.074801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/06/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Particle accelerators that use electromagnetic fields to increase a charged particle's energy have greatly advanced the development of science and industry since invention. However, the enormous cost and size of conventional radio-frequency accelerators have limited their accessibility. Here, we demonstrate a miniaccelerator powered by terahertz pulses with wavelengths 100 times shorter than radio-frequency pulses. By injecting a short relativistic electron bunch to a 30-mm-long dielectric-lined waveguide and tuning the frequency of a 20-period terahertz pulse to the phase-velocity-matched value, precise and sustained acceleration for nearly 100% of the electrons is achieved with the beam energy spread essentially unchanged. Furthermore, by accurately controlling the phase of two terahertz pulses, the beam is stably accelerated successively in two dielectric waveguides with close to 100% charge coupling efficiency. Our results demonstrate stable and scalable beam acceleration in a multistage miniaccelerator and pave the way for functioning terahertz-driven high-energy accelerators.
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Affiliation(s)
- Heng Tang
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lingrong Zhao
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Pengfei Zhu
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiao Zou
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jia Qi
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Ya Cheng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Jiaqi Qiu
- Nuctech Company Limited, Beijing 100084, China
| | - Xianggang Hu
- Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an, Shanxi 710024, China
| | - Wei Song
- Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an, Shanxi 710024, China
| | - Dao Xiang
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jie Zhang
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
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40
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Hira Y, Monnai Y. Sub-terahertz vortex beam generation using a spiral metal reflector. OPTICS EXPRESS 2021; 29:24118-24128. [PMID: 34614662 DOI: 10.1364/oe.430805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate sub-terahertz vortex beam generation using a spiral metal reflector that can be used for both polarizations. A vortex beam is a ring-shaped beam that possesses sub-wavelength null in the center formed by angular phase variation. While the sub-terahertz vortex beams have gained increasing attention for a wide range of applications in sensing and communications, techniques for generating them are still accompanied by challenges. For example, the use of a phase plate, which is common in the optical regime, suffers from intrinsic losses of dielectric materials in the sub-terahertz regime. Moreover, holographic diffraction gratings, which could replace transmissive components, are inefficient and sensitive to the polarization. To reconcile these challenges, here we design a reflector type metal component with a spiral surface shape. We firstly derive a direct equation to design its shape. We then experimentally validate the design by mapping the radiation pattern of a vortex beam for the WR10 frequency band (75 to 110 GHz) in both of the orthogonal polarizations. The result confirms an inexpensive and versatile approach to generate a vortex beam in the sub-terahertz regime.
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41
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Singh A, Li J, Pashkin A, Rana R, Winnerl S, Helm M, Schneider H. High-field THz pulses from a GaAs photoconductive emitter for non-linear THz studies. OPTICS EXPRESS 2021; 29:19920-19927. [PMID: 34266092 DOI: 10.1364/oe.427247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/09/2021] [Indexed: 06/13/2023]
Abstract
We report the emission of high-field terahertz pulses from a GaAs large-area photoconductive emitter pumped with a Ti:Sapphire amplifier laser system at 800 nm wavelength and 1 kHz repetition rate. The maximum estimated terahertz electric field at the focus is ≳ 230 kV/cm. We also demonstrate the capability of the terahertz field to cause a non-linear effect, which usually requires high-field terahertz pulses generated through optical rectification or an air plasma. A significant drop in the optical conductivity of optically pumped GaAs due to Γ-L inter-valley scattering of free electrons caused by the strong THz field is found.
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42
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Chen Y, He Y, Zhang Y, Tian Z, Dai J. Systematic investigation of terahertz wave generation from liquid water lines. OPTICS EXPRESS 2021; 29:20477-20486. [PMID: 34266136 DOI: 10.1364/oe.425207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
Understanding the process of terahertz (THz) wave generation from liquid water is crucial for further developing liquid THz sources. We present a systematic investigation of THz wave generated from laser-irradiated water lines. We show that water line in the diameter range of 0.1-0.2 mm generates the strongest THz wave, and THz frequency red shift is observed when diameter of the water line increases. The pump pulse energy dependence is decoupled from self-focusing effect by compensating the focal point displacement. As the pump pulse energy increases, saturation effect in THz peak electric field is observed, which can be mainly attributed to the intensity clamping effect inside the plasma and have never been reported previously, using water line or water film as the THz source. The proposed mechanism for saturation is supported by an independent measurement of laser pulse spectrum broadening. This work may help to further understand the laser-liquid interaction in THz generation process.
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43
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Wulf F, Hoffmann M, Saraceno CJ. Analysis of THz generation using the tilted-pulse-front geometry in the limit of small pulse energies and beam sizes. OPTICS EXPRESS 2021; 29:18889-18904. [PMID: 34154135 DOI: 10.1364/oe.426228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/12/2021] [Indexed: 06/13/2023]
Abstract
Optical rectification in lithium niobate using the tilted-pulse-front geometry is one of the most commonly used techniques for efficient generation of energetic single-cycle THz pulses and the details of this generation scheme are well understood for high pulse energy driving lasers, such as mJ-class, kHz-repetition rate Ti:Sa amplifier systems. However, as modern Yb-based laser systems with ever increasing repetition rate become available, other excitation regimes become relevant. In particular, the use of more moderate pulse energies (in the few µJ to multi-10 µJ regime), available nowadays by laser systems with MHz repetition rates, have never been thoroughly explored. As increasing the repetition rate of THz sources for spectroscopy becomes more relevant in the community, we present a thorough numerical analysis of this regime using a 2+1-D numerical model. Our work allows us to confirm experimental trends observed in this unusual excitation regime and shows that the conversion efficiency is naturally limited by the small pump beam sizes as a consequence of spatial walk-off between the pump and THz beams. Based on our findings, we discuss strategies to overcome the current limitations, which will pave the way for powerful THz sources approaching the watt level with multi-MHz repetition rates.
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Niwa H, Yoshikawa N, Kawaguchi M, Hayashi M, Shimano R. Switchable generation of azimuthally- and radially-polarized terahertz beams from a spintronic terahertz emitter. OPTICS EXPRESS 2021; 29:13331-13343. [PMID: 33985069 DOI: 10.1364/oe.422484] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
We propose and demonstrate a method of generating two fundamental terahertz cylindrical vector beams (THz-CVBs), namely the azimuthally- and radially-polarized THz pulses, from a spintronic THz emitter. We begin by presenting that the spintronic emitter generates the HE21 mode, a quadrupole like polarization distribution, when placed between two magnets with opposing polarity. By providing an appropriate mode conversion using a triangular Si prism, we show both from experiment and numerical calculation that we obtain azimuthal and radial THz vector beams. The proposed method facilitates the access of CVBs and paves the way toward sophisticated polarization control in the THz regime.
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Tian Q, Xu H, Wang Y, Liang Y, Tan Y, Ning X, Yan L, Du Y, Li R, Hua J, Huang W, Tang C. Efficient generation of a high-field terahertz pulse train in bulk lithium niobate crystals by optical rectification. OPTICS EXPRESS 2021; 29:9624-9634. [PMID: 33820386 DOI: 10.1364/oe.419709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/07/2021] [Indexed: 06/12/2023]
Abstract
We demonstrate a highly efficient method for the generation of a high-field terahertz (THz) pulse train via optical rectification (OR) in congruent lithium niobate (LN) crystals driven by temporally shaped laser pulses. A narrowband THz pulse has been successfully achieved with sub-percent level conversion efficiency and multi MV/cm peak field at 0.26 THz. For the single-cycle THz generation, we achieved a THz pulse with 373-μJ energy in a LN crystal excited by a 100-mJ laser pulse at room temperature. The conversion efficiency is further improved to 0.77 % pumped by a 20-mJ laser pulse with a smaller pump beam size (6 mm in horizontal and 15 mm in vertical). This method holds great potential for generating mJ-level narrow-band THz pulse trains, which may have a major impact in mJ-scale applications like terahertz-based accelerators and light sources.
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Jin Q, Yiwen E, Zhang XC. Terahertz aqueous photonics. FRONTIERS OF OPTOELECTRONICS 2021; 14:37-63. [PMID: 36637782 PMCID: PMC9743863 DOI: 10.1007/s12200-020-1070-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/13/2020] [Indexed: 05/14/2023]
Abstract
Developing efficient and robust terahertz (THz) sources is of incessant interest in the THz community for their wide applications. With successive effort in past decades, numerous groups have achieved THz wave generation from solids, gases, and plasmas. However, liquid, especially liquid water has never been demonstrated as a THz source. One main reason leading the impediment is that water has strong absorption characteristics in the THz frequency regime.A thin water film under intense laser excitation was introduced as the THz source to mitigate the considerable loss of THz waves from the absorption. Laser-induced plasma formation associated with a ponderomotive force-induced dipole model was proposed to explain the generation process. For the one-color excitation scheme, the water film generates a higher THz electric field than the air does under the identical experimental condition. Unlike the case of air, THz wave generation from liquid water prefers a sub-picosecond (200-800 fs) laser pulse rather than a femtosecond pulse (~50 fs). This observation results from the plasma generation process in water.For the two-color excitation scheme, the THz electric field is enhanced by one-order of magnitude in comparison with the one-color case. Meanwhile, coherent control of the THz field is achieved by adjusting the relative phase between the fundamental pulse and the second-harmonic pulse.To eliminate the total internal reflection of THz waves at the water-air interface of a water film, a water line produced by a syringe needle was used to emit THz waves. As expected, more THz radiation can be coupled out and detected. THz wave generation from other liquids were also tested.
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Affiliation(s)
- Qi Jin
- The Institute of Optics, University of Rochester, Rochester, NY 14627 USA
| | - E. Yiwen
- The Institute of Optics, University of Rochester, Rochester, NY 14627 USA
| | - Xi-Cheng Zhang
- The Institute of Optics, University of Rochester, Rochester, NY 14627 USA
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Totero Gongora JS, Peters L, Tunesi J, Cecconi V, Clerici M, Pasquazi A, Peccianti M. All-Optical Two-Color Terahertz Emission from Quasi-2D Nonlinear Surfaces. PHYSICAL REVIEW LETTERS 2020; 125:263901. [PMID: 33449780 DOI: 10.1103/physrevlett.125.263901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/22/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
Two-color terahertz (THz) generation is a field-matter process combining an optical pulse and its second harmonic. Its application in condensed matter is challenged by the lack of phase matching among multiple interacting fields. Here, we demonstrate phase-matching-free two-color THz conversion in condensed matter by introducing a highly resonant absorptive system. The generation is driven by a third-order nonlinear interaction localized at the surface of a narrow-band-gap semiconductor, and depends directly on the relative phase between the two colors. We show how to isolate the third-order effect among other competitive THz-emitting surface mechanisms, exposing the general features of the two-color process.
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Affiliation(s)
- J S Totero Gongora
- Emergent Photonics Lab (EPic), Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, United Kingdom
| | - L Peters
- Emergent Photonics Lab (EPic), Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, United Kingdom
| | - J Tunesi
- Emergent Photonics Lab (EPic), Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, United Kingdom
| | - V Cecconi
- Emergent Photonics Lab (EPic), Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, United Kingdom
| | - M Clerici
- Ultrafast Nonlinear Optics Lab (UNO), James Watt School of Engineering, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - A Pasquazi
- Emergent Photonics Lab (EPic), Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, United Kingdom
| | - M Peccianti
- Emergent Photonics Lab (EPic), Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, United Kingdom
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Fedorov VY, Tzortzakis S. Powerful terahertz waves from long-wavelength infrared laser filaments. LIGHT, SCIENCE & APPLICATIONS 2020; 9:186. [PMID: 33298833 PMCID: PMC7665013 DOI: 10.1038/s41377-020-00423-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/11/2020] [Accepted: 10/19/2020] [Indexed: 06/02/2023]
Abstract
Strong terahertz (THz) electric and magnetic transients open up new horizons in science and applications. We review the most promising way of achieving sub-cycle THz pulses with extreme field strengths. During the nonlinear propagation of two-color mid-infrared and far-infrared ultrashort laser pulses, long, and thick plasma strings are produced, where strong photocurrents result in intense THz transients. The corresponding THz electric and magnetic field strengths can potentially reach the gigavolt per centimeter and kilotesla levels, respectively. The intensities of these THz fields enable extreme nonlinear optics and relativistic physics. We offer a comprehensive review, starting from the microscopic physical processes of light-matter interactions with mid-infrared and far-infrared ultrashort laser pulses, the theoretical and numerical advances in the nonlinear propagation of these laser fields, and the most important experimental demonstrations to date.
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Affiliation(s)
- Vladimir Yu Fedorov
- Science Program, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow, 119991, Russia.
| | - Stelios Tzortzakis
- Science Program, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.
- Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1527, Heraklion, GR-71110, Greece.
- Department of Materials Science and Technology, University of Crete, Heraklion, GR-71003, Greece.
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Ovchinnikov AV, Chefonov OV, Agranat MB, Fortov VE, Jazbinsek M, Hauri CP. Generation of strong-field spectrally tunable terahertz pulses. OPTICS EXPRESS 2020; 28:33921-33936. [PMID: 33182871 DOI: 10.1364/oe.405545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/17/2020] [Indexed: 06/11/2023]
Abstract
The ideal laser source for nonlinear terahertz spectroscopy offers large versatility delivering both ultra-intense broadband single-cycle pulses and user-selectable multi-cycle pulses at narrow linewidths. Here we show a highly versatile terahertz laser platform providing single-cycle transients with tens of MV/cm peak field as well as spectrally narrow pulses, tunable in bandwidth and central frequency across 5 octaves at several MV/cm field strengths. The compact scheme is based on optical rectification in organic crystals of a temporally modulated laser beam. It allows up to 50 cycles and central frequency tunable from 0.5 to 7 terahertz, with a minimum width of 30 GHz, corresponding to the photon-energy width of ΔE=0.13 meV and the spectroscopic-wavenumber width of Δ(λ-1)=1.1 cm-1. The experimental results are excellently predicted by theoretical modelling. Our table-top source shows similar performances to that of large-scale terahertz facilities but offering in addition more versatility, multi-colour femtosecond pump-probe opportunities and ultralow timing jitter.
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O Krizsán G, Tibai Z, Hebling J, Pálfalvi L, Almási G, Tóth G. Lithium niobate and lithium tantalate based scalable terahertz pulse sources in reflection geometry. OPTICS EXPRESS 2020; 28:34320-34327. [PMID: 33182904 DOI: 10.1364/oe.405748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/18/2020] [Indexed: 06/11/2023]
Abstract
A new type of THz source, working in reflection geometry, is proposed, where the pulse-front-tilt is introduced by a periodically micro-structured metal profile. For optical coupling, high refractive index nanocomposite fluid is used between the nonlinear optical material and the structured metal surface. Numerical simulations predict ∼87 and ∼85% optimized diffraction efficiencies for lithium niobate and lithium tantalate at 1030 and 800 nm pump wavelengths. The largest diffraction efficiencies can be achieved for a larger refractive index of the nanocomposite fluid than the index of the nonlinear material, for both cases. THz generation efficiencies of ∼3 and ∼1% are predicted for lithium niobate and lithium tantalate, respectively.
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