1
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Davies CS, Kirilyuk A. Epsilon-near-zero regime for ultrafast opto-spintronics. NPJ SPINTRONICS 2024; 2:20. [PMID: 38883427 PMCID: PMC11177794 DOI: 10.1038/s44306-024-00025-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/11/2024] [Indexed: 06/18/2024]
Abstract
Over the last two decades, breakthrough works in the field of non-linear phononics have revealed that high-frequency lattice vibrations, when driven to high amplitude by mid- to far-infrared optical pulses, can bolster the light-matter interaction and thereby lend control over a variety of spontaneous orderings. This approach fundamentally relies on the resonant excitation of infrared-active transverse optical phonon modes, which are characterized by a maximum in the imaginary part of the medium's permittivity. Here, in this Perspective article, we discuss an alternative strategy where the light pulses are instead tailored to match the frequency at which the real part of the medium's permittivity goes to zero. This so-called epsilon-near-zero regime, popularly studied in the context of metamaterials, naturally emerges to some extent in all dielectric crystals in the infrared spectral range. We find that the light-matter interaction in the phononic epsilon-near-zero regime becomes strongly enhanced, yielding even the possibility of permanently switching both spin and polarization order parameters. We provide our perspective on how this hitherto-neglected yet fertile research area can be explored in future, with the aim to outline and highlight the exciting challenges and opportunities ahead.
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Affiliation(s)
- C S Davies
- FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
- Radboud University, Institute for Molecules and Materials, Nijmegen, The Netherlands
| | - A Kirilyuk
- FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
- Radboud University, Institute for Molecules and Materials, Nijmegen, The Netherlands
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2
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Wach Q, Quick MT, Ayari S, Achtstein AW. Field-dependent THz transport nonlinearities in semiconductor nano structures. Phys Chem Chem Phys 2024; 26:13995-14005. [PMID: 38683165 DOI: 10.1039/d4cp00952e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
Charge transport nonlinearities in semiconductor quantum dots and nanorods are studied. Using a density matrix formalism, we retrieve the field-dependent nonlinear mobility and show the possibility of intra-pulse gain. We further demonstrate that the dynamics of master equations can be captured in an analytical formula for the field-dependent charge carrier mobility, e.g. for two-level systems. This equation extends the linear response theory based Kubo-Greenwood result to nonlinear processes at elevated field strength, easily reached in THz transport spectroscopy. With these tools we analyze the field strength, chirp, temperature and dephasing dependence of the charge carrier mobility in the model system of CdSe quantum dots and wires. Stark broadening and Rabi splitting result in strong alterations of the mobility spectra, pronounced at low temperatures. The mobility spectra are strongly temperature and pulse shape dependent in the nonlinear regime. The findings are of immediate interest e.g. for nonlinear THz generation, conversion and amplification in 6G technology and nano electronics. Our results further enable experimentalists to fit and understand measured charge transport nonlinearities with analytical expressions and to design nanosystems with engineered material properties.
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Affiliation(s)
- Quentin Wach
- Institute of Optics and Atomic Physics, Technische Universität Berlin, 10623 Berlin, Germany
| | - Michael T Quick
- Institute of Optics and Atomic Physics, Technische Universität Berlin, 10623 Berlin, Germany
| | - Sabrine Ayari
- Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Alexander W Achtstein
- Institute of Optics and Atomic Physics, Technische Universität Berlin, 10623 Berlin, Germany
- Fakultät für Physik, Universität Bielefeld, Universitätsstr. 25, 33615 Bielefeld, Germany.
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3
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Novelli F. Terahertz spectroscopy of thick and diluted water solutions. OPTICS EXPRESS 2024; 32:11041-11056. [PMID: 38570962 DOI: 10.1364/oe.510393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/16/2024] [Indexed: 04/05/2024]
Abstract
While bright terahertz sources are used to perform nonlinear experiments, they can be advantageous for high-precision linear measurements of opaque samples. By placing the sample away from the focus, nonlinearities can be suppressed, and sizeable amounts of transmitted radiation detected. Here, this approach is demonstrated for a 0.5 mm thick layer of liquid water in a static sample holder. Variations of the index of refraction as small as (7 ± 2) · 10-4 were detected at 0.58 THz for an aqueous salt solution containing ten millimoles of sodium chloride. To my knowledge, this precision is unprecedented in time-domain spectroscopy studies of diluted aqueous systems or other optically thick and opaque materials.
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4
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Luo J, Lin T, Zhang J, Chen X, Blackert ER, Xu R, Yakobson BI, Zhu H. Large effective magnetic fields from chiral phonons in rare-earth halides. Science 2023; 382:698-702. [PMID: 37943931 DOI: 10.1126/science.adi9601] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 09/07/2023] [Indexed: 11/12/2023]
Abstract
Time-reversal symmetry (TRS) is pivotal for materials' optical, magnetic, topological, and transport properties. Chiral phonons, characterized by atoms rotating unidirectionally around their equilibrium positions, generate dynamic lattice structures that break TRS. Here, we report that coherent chiral phonons, driven by circularly polarized terahertz light pulses, polarize the paramagnetic spins in cerium fluoride in a manner similar to that of a quasi-static magnetic field on the order of 1 tesla. Through time-resolved Faraday rotation and Kerr ellipticity, we found that the transient magnetization is only excited by pulses resonant with phonons, proportional to the angular momentum of the phonons, and growing with magnetic susceptibility at cryogenic temperatures. The observation quantitatively agrees with our spin-phonon coupling model and may enable new routes to investigating ultrafast magnetism, energy-efficient spintronics, and nonequilibrium phases of matter with broken TRS.
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Affiliation(s)
- Jiaming Luo
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
- Applied Physics Graduate Program, Rice University, Houston, Texas 77005, USA
| | - Tong Lin
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
| | - Junjie Zhang
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
| | - Xiaotong Chen
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
| | - Elizabeth R Blackert
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
| | - Rui Xu
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
| | - Boris I Yakobson
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
| | - Hanyu Zhu
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX 77005, USA
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5
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Miyamoto T, Kondo A, Inaba T, Morimoto T, You S, Okamoto H. Terahertz radiation by quantum interference of excitons in a one-dimensional Mott insulator. Nat Commun 2023; 14:6229. [PMID: 37833316 PMCID: PMC10575914 DOI: 10.1038/s41467-023-41463-8] [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: 09/22/2022] [Accepted: 09/01/2023] [Indexed: 10/15/2023] Open
Abstract
Nearly monocyclic terahertz waves are used for investigating elementary excitations and for controlling electronic states in solids. They are usually generated via second-order optical nonlinearity by injecting a femtosecond laser pulse into a nonlinear optical crystal. In this framework, however, it is difficult to control phase and frequency of terahertz waves. Here, we show that in a one-dimensional Mott insulator of a nickel-bromine chain compound a terahertz wave is generated with high efficiency via strong electron modulations due to quantum interference between odd-parity and even-parity excitons produced by two-color femtosecond pulses. Using this method, one can control all of the phase, frequency, and amplitude of terahertz waves by adjusting the creation-time difference of two excitons with attosecond accuracy. This approach enables to evaluate the phase-relaxation time of excitons under strong electron correlations in Mott insulators. Moreover, phase- and frequency-controlled terahertz pulses are beneficial for coherent electronic-state controls with nearly monocyclic terahertz waves.
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Affiliation(s)
- Tatsuya Miyamoto
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan.
| | - Akihiro Kondo
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - Takeshi Inaba
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - Takeshi Morimoto
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - Shijia You
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan
| | - Hiroshi Okamoto
- Department of Advanced Materials Science, University of Tokyo, Chiba, 277-8561, Japan.
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6
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Zhou X, Lin Y, Chan Y, Deng F, Zhang J. Coherent generation and control of tunable narrowband THz radiation from a laser-induced air-plasma filament. OPTICS LETTERS 2023; 48:2881-2884. [PMID: 37262234 DOI: 10.1364/ol.488811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/25/2023] [Indexed: 06/03/2023]
Abstract
We report on the proof-of-principle experiment of generating carrier-envelope phase (CEP)-controllable and frequency-tunable narrowband terahertz (THz) radiation from an air-plasma filament prescribed by the beat of a temporally stretched two-color laser pulse sequence. The pulse sequence was prepared by propagating the fundamental ultrafast laser pulse through a grating stretcher and Michelson interferometer with variable inter-arm delay. By partially frequency-doubling and focusing the pulse sequence, an air-plasma filament riding a beat note was created to radiate a THz wave with primary pulse characteristics (center frequency and CEP) under coherent control. To reproduce experimental results and elucidate complex nonlinear light-matter interaction, numerical simulation has been performed. This work demonstrates the feasibility of generating coherently controlled narrowband THz wave with high tunability in laser-induced air plasma.
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7
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Disa AS, Curtis J, Fechner M, Liu A, von Hoegen A, Först M, Nova TF, Narang P, Maljuk A, Boris AV, Keimer B, Cavalleri A. Photo-induced high-temperature ferromagnetism in YTiO 3. Nature 2023; 617:73-78. [PMID: 37138109 PMCID: PMC10156606 DOI: 10.1038/s41586-023-05853-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 02/16/2023] [Indexed: 05/05/2023]
Abstract
In quantum materials, degeneracies and frustrated interactions can have a profound impact on the emergence of long-range order, often driving strong fluctuations that suppress functionally relevant electronic or magnetic phases1-7. Engineering the atomic structure in the bulk or at heterointerfaces has been an important research strategy to lift these degeneracies, but these equilibrium methods are limited by thermodynamic, elastic and chemical constraints8. Here we show that all-optical, mode-selective manipulation of the crystal lattice can be used to enhance and stabilize high-temperature ferromagnetism in YTiO3, a material that shows only partial orbital polarization, an unsaturated low-temperature magnetic moment and a suppressed Curie temperature, Tc = 27 K (refs. 9-13). The enhancement is largest when exciting a 9 THz oxygen rotation mode, for which complete magnetic saturation is achieved at low temperatures and transient ferromagnetism is realized up to Tneq > 80 K, nearly three times the thermodynamic transition temperature. We interpret these effects as a consequence of the light-induced dynamical changes to the quasi-degenerate Ti t2g orbitals, which affect the magnetic phase competition and fluctuations found in the equilibrium state14-20. Notably, the light-induced high-temperature ferromagnetism discovered in our work is metastable over many nanoseconds, underscoring the ability to dynamically engineer practically useful non-equilibrium functionalities.
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Affiliation(s)
- A S Disa
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA.
| | - J Curtis
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- College of Letters and Science, University of California, Los Angeles, CA, USA
| | - M Fechner
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - A Liu
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - A von Hoegen
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - T F Nova
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - P Narang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- College of Letters and Science, University of California, Los Angeles, CA, USA
| | - A Maljuk
- Leibniz Institute for Solid State and Materials Research Dresden, Dresden, Germany
| | - A V Boris
- Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - B Keimer
- Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
- Clarendon Laboratory, Department of Physics, Oxford University, Oxford, UK.
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8
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Le J, Su Y, Tian C, Kung AH, Shen YR. A novel scheme for ultrashort terahertz pulse generation over a gapless wide spectral range: Raman-resonance-enhanced four-wave mixing. LIGHT, SCIENCE & APPLICATIONS 2023; 12:34. [PMID: 36732493 PMCID: PMC9894857 DOI: 10.1038/s41377-023-01071-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/28/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Abstract
Ultrashort energetic terahertz (THz) pulses have created an exciting new area of research on light interactions with matter. For material studies in small laboratories, widely tunable femtosecond THz pulses with peak field strength close to MV cm-1 are desired. Currently, they can be largely acquired by optical rectification and difference frequency generation in crystals without inversion symmetry. We describe in this paper a novel scheme of THz pulse generation with no frequency tuning gap based on Raman-resonance-enhanced four-wave mixing in centrosymmetric media, particularly diamond. We show that we could generate highly stable, few-cycle pulses with near-Gaussian spatial and temporal profiles and carrier frequency tunable from 5 to >20 THz. They had a stable and controllable carrier-envelop phase and carried ~15 nJ energy per pulse at 10 THz (with a peak field strength of ~1 MV cm-1 at focus) from a 0.5-mm-thick diamond. The measured THz pulse characteristics agreed well with theoretical predictions. Other merits of the scheme are discussed, including the possibility of improving the THz output energy to a much higher level.
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Affiliation(s)
- Jiaming Le
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro- and Nano-Photonic Structure (MOE), Fudan University, Shanghai, 200433, China
| | - Yudan Su
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Chuanshan Tian
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro- and Nano-Photonic Structure (MOE), Fudan University, Shanghai, 200433, China.
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, China.
| | - A H Kung
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro- and Nano-Photonic Structure (MOE), Fudan University, Shanghai, 200433, China
| | - Y Ron Shen
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro- and Nano-Photonic Structure (MOE), Fudan University, Shanghai, 200433, China.
- Department of Physics, University of California, Berkeley, CA, 94720, USA.
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9
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Rader C, Nielson MF, Knighton BE, Zaccardi ZB, Michaelis DJ, Johnson JA. Custom terahertz waveforms using complementary organic nonlinear optical crystals. OPTICS LETTERS 2022; 47:5985-5988. [PMID: 37219153 DOI: 10.1364/ol.474343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/14/2022] [Indexed: 05/24/2023]
Abstract
Organic nonlinear optical (NLO) crystals are among the most efficient (>1%) terahertz (THz) radiation generators. However, one of the limitations of using organic NLO crystals is that the unique THz absorptions in each crystal make it difficult to obtain a strong, smooth, and broad emission spectrum. In this work, we combine THz pulses from two complementary crystals, DAST and PNPA, to effectively fill in spectral gaps, creating a smooth spectrum with frequencies out to 5 THz. The combination of pulses also increases the peak-to-peak field strength from 1 MV/cm to 1.9 MV/cm.
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10
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Murotani Y, Kanda N, Ikeda TN, Matsuda T, Goyal M, Yoshinobu J, Kobayashi Y, Stemmer S, Matsunaga R. Stimulated Rayleigh Scattering Enhanced by a Longitudinal Plasma Mode in a Periodically Driven Dirac Semimetal Cd_{3}As_{2}. PHYSICAL REVIEW LETTERS 2022; 129:207402. [PMID: 36461987 DOI: 10.1103/physrevlett.129.207402] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/06/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
Using broadband (12-45 THz) multi-terahertz spectroscopy, we show that stimulated Rayleigh scattering dominates the transient optical conductivity of cadmium arsenide, a Dirac semimetal, under an optical driving field at 30 THz. The characteristic dispersive line shape with net optical gain is accounted for by optical transitions between light-induced Floquet subbands, strikingly enhanced by the longitudinal plasma mode. Stimulated Rayleigh scattering with an unprecedentedly large refractive index change may pave the way for slow light generation in conductive solids at room temperature.
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Affiliation(s)
- Yuta Murotani
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Natsuki Kanda
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - Tatsuhiko N Ikeda
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Takuya Matsuda
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Manik Goyal
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | - Jun Yoshinobu
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Yohei Kobayashi
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Susanne Stemmer
- Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | - Ryusuke Matsunaga
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
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11
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Lin HW, Mead G, Blake GA. Mapping LiNbO_{3} Phonon-Polariton Nonlinearities with 2D THz-THz-Raman Spectroscopy. PHYSICAL REVIEW LETTERS 2022; 129:207401. [PMID: 36461997 DOI: 10.1103/physrevlett.129.207401] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 10/07/2022] [Indexed: 06/17/2023]
Abstract
Two-dimensional terahertz-terahertz-Raman spectroscopy can provide insight into the anharmonicities of low-energy phonon modes-knowledge of which can help develop strategies for coherent control of material properties. Measurements on LiNbO_{3} reveal THz and Raman nonlinear transitions between the E(TO_{1}) and E(TO_{3}) phonon polaritons. Distinct coherence pathways are observed with different THz polarizations. The observed pathways suggest that the origin of the third-order nonlinear responses is due to mechanical anharmonicities, as opposed to electronic anharmonicities. Further, we confirm that the E(TO_{1}) and E(TO_{3}) phonon polaritons are excited through resonant one-photon THz excitation.
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Affiliation(s)
- Haw-Wei Lin
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Griffin Mead
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Geoffrey A Blake
- Division of Chemistry and Chemical Engineering and Division of Geology and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
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12
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Seo M, Mun JH, Heo J, Kim DE. High-efficiency near-infrared optical parametric amplifier for intense, narrowband THz pulses tunable in the 4 to 19 THz region. Sci Rep 2022; 12:16273. [PMID: 36175458 PMCID: PMC9523057 DOI: 10.1038/s41598-022-20622-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/15/2022] [Indexed: 11/19/2022] Open
Abstract
Dynamic control of material properties using strong-field, narrowband THz sources has drawn attention because it allows selective manipulation of quantum states on demand by coherent excitation of specific low-energy modes in solids. Yet, the lack of powerful narrowband lasers with frequencies in the range of a few to a few tens of THz has restricted the exploration of hidden states in condensed matter. Here, we report the optimization of an optical parametric amplifier (OPA) and the efficient generation of a strong, narrowband THz field. The OPA has a total conversion efficiency of > 55%, which is the highest value reported to date, with an excellent energy-stability of 0.7% RMS over 3 h. We found that the injection of a high-energy signal beam to a power amplification stage in an OPA leads to high-efficiency and a super-Gaussian profile. By difference-frequency generation of two chirped OPA signal pulses in an organic nonlinear crystal, we obtained a THz pulse with an energy of 3.2 μJ, a bandwidth of 0.5 THz, and a pulse duration of 860 fs tunable between the 4 and 19 THz regions. This corresponds to an internal THz conversion efficiency of 0.4% and a THz field strength of 6.7 MV/cm. This approach demonstrates an effective way to generate narrow-bandwidth, intense THz fields.
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Affiliation(s)
- Meenkyo Seo
- Department of Physics and Center for Attosecond Science and Technology, POSTECH, Pohang, 37673, South Korea.,Max Planck POSTECH/KOREA Research Initiative, Pohang, 37673, South Korea
| | - Je-Hoi Mun
- Department of Physics and Center for Attosecond Science and Technology, POSTECH, Pohang, 37673, South Korea.,Max Planck POSTECH/KOREA Research Initiative, Pohang, 37673, South Korea
| | - Jaeuk Heo
- Department of Physics and Center for Attosecond Science and Technology, POSTECH, Pohang, 37673, South Korea.,Max Planck POSTECH/KOREA Research Initiative, Pohang, 37673, South Korea
| | - Dong Eon Kim
- Department of Physics and Center for Attosecond Science and Technology, POSTECH, Pohang, 37673, South Korea. .,Max Planck POSTECH/KOREA Research Initiative, Pohang, 37673, South Korea.
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13
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Ishizuka H, Sato M. Large Photogalvanic Spin Current by Magnetic Resonance in Bilayer Cr Trihalides. PHYSICAL REVIEW LETTERS 2022; 129:107201. [PMID: 36112457 DOI: 10.1103/physrevlett.129.107201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/08/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Spin current is a key to realizing various phenomena and functionalities related to spintronics. Recently, the possibility of generating spin current through a photogalvanic effect of magnons was pointed out theoretically. However, neither a candidate material nor a general formula for calculating the photogalvanic spin current in materials is known so far. In this Letter, we develop a general formula for the photogalvanic spin current through a magnetic resonance process. This mechanism involves a one-magnon excitation process in contrast to the two-particle processes studied in earlier works. Using the formula, we show that GHz and THz waves create a large photogalvanic spin current in the antiferromagnetic phase of bilayer CrI_{3} and CrBr_{3}. The large spin current arises from an optical process involving two magnon bands, which is a contribution unknown to date. This spin current appears only in the antiferromagnetic ordered phase and is reversible by controlling the order parameter. These results open a route to material design for the photogalvanic effect of magnetic excitations.
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Affiliation(s)
- Hiroaki Ishizuka
- Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo, 152-8551, Japan
| | - Masahiro Sato
- Department of Physics, Ibaraki University, Mito, Ibaraki 310-8512, Japan
- Department of Physics, Chiba University, Chiba 263-8522, Japan
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14
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Dong T, Zhang SJ, Wang NL. Recent Development of Ultrafast Optical Characterizations for Quantum Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2110068. [PMID: 35853841 DOI: 10.1002/adma.202110068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 06/09/2022] [Indexed: 06/15/2023]
Abstract
The advent of intense ultrashort optical pulses spanning a frequency range from terahertz to the visible has opened a new era in the experimental investigation and manipulation of quantum materials. The generation of strong optical field in an ultrashort time scale enables the steering of quantum materials nonadiabatically, inducing novel phenomenon or creating new phases which may not have an equilibrium counterpart. Ultrafast time-resolved optical techniques have provided rich information and played an important role in characterization of the nonequilibrium and nonlinear properties of solid systems. Here, some of the recent progress of ultrafast optical techniques and their applications to the detection and manipulation of physical properties in selected quantum materials are reviewed. Specifically, the new development in the detection of the Higgs mode and photoinduced nonequilibrium response in the study of superconductors by time-resolved terahertz spectroscopy are discussed.
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Affiliation(s)
- Tao Dong
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Si-Jie Zhang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Nan-Lin Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing, 100913, China
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15
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Kojima O, Tarui Y, Kita T, Majeed A, Ivanov P, Clarke E, Hogg RA. Increase in terahertz-wave intensity in a magnetic field due to difference-frequency mixing by exciton excitation in a GaAs/AlAs multiple quantum well. OPTICS EXPRESS 2022; 30:11789-11796. [PMID: 35473114 DOI: 10.1364/oe.453812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Magnetic fields can increase the intensity of terahertz (THz) waves due to changing the dipole moment direction using the Lorentz force. This study reports the increase in the THz-wave intensity generated by differential frequency mixing using commercial permanent magnets under exciton-excitation. While a weak magnetic field applied to a multiple quantum well increases the THz-wave intensity due to excitons, a strong field causes its decrease. According to the calculations, the increase is caused by the electron-hole separation due to the Lorentz force. Furthermore, the calculations suggest the importance of carrier acceleration to enhance the intensity. Importantly, the increase in the THz-wave intensity due to differential frequency mixing does not require a strong magnetic field and can be achieved with inexpensive commercially available magnets.
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16
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Novelli F, Hoberg C, Adams EM, Klopf JM, Havenith M. Terahertz pump-probe of liquid water at 12.3 THz. Phys Chem Chem Phys 2021; 24:653-665. [PMID: 34570144 PMCID: PMC9096911 DOI: 10.1039/d1cp03207k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The dynamical complexity of the hydrogen-bonded water network can be investigated with intense Terahertz (THz) spectroscopy, which can drive the liquid into the nonlinear response regime and probe anharmonicity effects. Here we report single-color and polarization-dependent pump–probe experiments at 12.3 THz on liquid water, exciting the librational mode. By comparing results obtained on a static sample and a free-flowing water jet, we are able to disentangle the distinct contributions by thermal, acoustic, and nonlinear optical effects. We show that the transient transmission by the static water layer on a time scale of hundreds of microseconds can be described by thermal (slow) and acoustic (temperature-dependent) effects. In addition, during pump probe overlap we observe an anisotropic nonlinear optical response. This nonlinear signal is more prominent in the liquid jet than in the static cell, where temperature and density perturbations are more pronounced. Our measurements confirm that the THz excitation resonates with the rotationally-damped motion of water molecules, resulting in enhanced transient anisotropy. This model can be used to explain the non-linear response of water in the frequency range between about 1 and 20 THz. The excitation on the librational band of liquid water at 12.3 THz resonates with the rotationally-damped motion of water molecules.![]()
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Affiliation(s)
- Fabio Novelli
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany.
| | - Claudius Hoberg
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany.
| | - Ellen M Adams
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany.
| | - J Michael Klopf
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr University Bochum, 44780 Bochum, Germany.
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17
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Particle-in-Cell Simulations of High-Power THz Generator Based on the Collision of Strongly Focused Relativistic Electron Beams in Plasma. PHOTONICS 2021. [DOI: 10.3390/photonics8060172] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Based on particle-in-cell simulations, we propose to generate sub-nanosecond pulses of narrowband terahertz radiation with tens of MW power using unique properties of kiloampere relativistic (2 MeV) electron beams produced by linear induction accelerators. Due to small emittance of such beams, they can be focused into millimeter and sub-millimeter spots comparable in sizes with the wavelength of THz radiation. If such a beam is injected into a plasma, it becomes unstable against the two-stream instability and excites plasma oscillations that can be converted to electromagnetic waves at the plasma frequency and its harmonics. It is shown that several radiation mechanisms with high efficiency of power conversion (∼1%) come into play when the radial size of the beam–plasma system becomes comparable with the wavelength of the emitted waves.
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18
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Zhang Y, Li K, Zhao H. Intense terahertz radiation: generation and application. FRONTIERS OF OPTOELECTRONICS 2021; 14:4-36. [PMID: 36637780 PMCID: PMC9743905 DOI: 10.1007/s12200-020-1052-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/20/2020] [Indexed: 05/30/2023]
Abstract
Strong terahertz (THz) radiation provides a powerful tool to manipulate and control complex condensed matter systems. This review provides an overview of progress in the generation, detection, and applications of intense THz radiation. The tabletop intense THz sources based on Ti:sapphire laser are reviewed, including photoconductive antennas (PCAs), optical rectification sources, plasma-based THz sources, and some novel techniques for THz generations, such as topological insulators, spintronic materials, and metasurfaces. The coherent THz detection methods are summarized, and their limitations for intense THz detection are analyzed. Applications of intense THz radiation are introduced, including applications in spectroscopy detection, nonlinear effects, and switching of coherent magnons. The review is concluded with a short perspective on the generation and applications of intense THz radiation.
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Affiliation(s)
- Yan Zhang
- Department of Physics, Beijing Key Laboratory for Metamaterials and Devices, Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, 100048, China.
| | - Kaixuan Li
- Department of Physics, Beijing Key Laboratory for Metamaterials and Devices, Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, 100048, China
| | - Huan Zhao
- Department of Physics, Beijing Key Laboratory for Metamaterials and Devices, Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, 100048, China
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19
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Tian W, Cirmi G, Olgun HT, Mutter P, Canalias C, Zukauskas A, Wang L, Kueny E, Ahr F, Calendron AL, Reichert F, Hasse K, Hua Y, Schimpf DN, Çankaya H, Pergament M, Hemmer M, Matlis N, Pasiskevicius V, Laurell F, Kärtner FX. µJ-level multi-cycle terahertz generation in a periodically poled Rb:KTP crystal. OPTICS LETTERS 2021; 46:741-744. [PMID: 33577503 DOI: 10.1364/ol.413410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
We demonstrate multi-cycle terahertz (MC-THz) generation in a 15.5 mm long periodically poled rubidium (Rb)-doped potassium titanyl phosphate (Rb:PPKTP) crystal with a poling period of 300 µm. By cryogenically cooling the crystal to 77 K, up to 0.72 µJ terahertz energy is obtained at a frequency of 0.5 THz with a 3 GHz bandwidth. A maximum internal optical-to-terahertz conversion efficiency of 0.16% is achieved, which is comparable with results achieved using periodically poled lithium niobate crystal. Neither photorefractive effects nor damage was observed with up to 900mJ/cm2, showing the great potential of Rb:PPKTP for multi-millijoule-level MC-THz generation.
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20
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Kanda N, Ishii N, Itatani J, Matsunaga R. Optical parametric amplification of phase-stable terahertz-to-mid-infrared pulses studied in the time domain. OPTICS EXPRESS 2021; 29:3479-3489. [PMID: 33770945 DOI: 10.1364/oe.413200] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
We report optical parametric amplification (OPA) of low-frequency infrared pulses in the intermediate region between terahertz (THz) frequency and mid-infrared (MIR), i.e., from 16.9 to 44.8 THz (6.7-17.8 μm). The 255-fs laser output of the Yb:KGW regenerative amplifier is compressed to 11-fs pulses using a multi-plate broadening scheme, which generates THz-to-MIR pulses with a spectrum extending to approximately 50 THz by intra-pulse differential frequency generation (DFG) in GaSe. The THz-to-MIR pulses are further amplified using a two-stage OPA in GaSe. The temporal dynamics and photocarrier effects during OPA are characterized in the time domain. Owing to the intra-pulse DFG, the long-term phase drift of the THz-to-MIR pulses after two-stage OPA is as small as 16 mrad during a 6-h operation without any active feedback. Our scheme using the intra-pulse DFG and post-amplification proposes a new route to intense THz-to-MIR light sources with extreme phase stability.
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21
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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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22
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Shin M, Kim WT, Kim S, Kim S, Yu IC, Kim S, Jazbinsek M, Yoon W, Yun H, Rotermund F, Kwon O. Organic Broadband THz Generators Optimized for Efficient Near-Infrared Optical Pumping. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2001738. [PMID: 33101871 PMCID: PMC7578856 DOI: 10.1002/advs.202001738] [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: 05/11/2020] [Revised: 07/06/2020] [Indexed: 06/11/2023]
Abstract
New organic THz generators are designed herein by molecular engineering of the refractive index, phonon mode, and spatial asymmetry. These benzothiazolium crystals simultaneously satisfy the crucial requirements for efficient THz wave generation, including having nonlinear optical chromophores with parallel alignment that provide large optical nonlinearity; good phase matching for enhancing the THz generation efficiency in the near-infrared region; strong intermolecular interactions that provide restraining THz self-absorption; high solubility that promotes good crystal growth ability; and a plate-like crystal morphology with excellent optical quality. Consequently, the as-grown benzothiazolium crystals exhibit excellent characteristics for THz wave generation, particularly at near-infrared pump wavelengths around 1100 nm, which is very promising given the availability of femtosecond laser sources at this wavelength, where current conventional THz generators deliver relatively low optical-to-THz conversion efficiencies. Compared to a 1.0-mm-thick ZnTe crystal as an inorganic benchmark, the 0.28-mm-thick benzothiazolium crystal yields a 19 times higher peak-to-peak THz electric field with a broader spectral bandwidth (>6.5 THz) when pumped at 1140 nm. The present work provides a valuable approach toward realizing organic crystals that can be pumped by near-infrared sources for efficient THz wave generation.
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Affiliation(s)
- Myeong‐Hoon Shin
- Department of Molecular Science and TechnologyAjou UniversitySuwon443‐749Korea
| | - Won Tae Kim
- Department of PhysicsKorea Advanced Institute of Science and Technology (KAIST)Daejeon34141Korea
| | - Se‐In Kim
- Department of Molecular Science and TechnologyAjou UniversitySuwon443‐749Korea
| | - Seung‐Jun Kim
- Department of Molecular Science and TechnologyAjou UniversitySuwon443‐749Korea
| | - In Cheol Yu
- Department of PhysicsKorea Advanced Institute of Science and Technology (KAIST)Daejeon34141Korea
| | - Sang‐Wook Kim
- Department of Molecular Science and TechnologyAjou UniversitySuwon443‐749Korea
| | - Mojca Jazbinsek
- Institute of Computational PhysicsZurich University of Applied Sciences (ZHAW)Winterthur8401Switzerland
| | - Woojin Yoon
- Department of Chemistry and Department of Energy Systems ResearchAjou UniversitySuwon443‐749Korea
| | - Hoseop Yun
- Department of Chemistry and Department of Energy Systems ResearchAjou UniversitySuwon443‐749Korea
| | - Fabian Rotermund
- Department of PhysicsKorea Advanced Institute of Science and Technology (KAIST)Daejeon34141Korea
| | - O‐Pil Kwon
- Department of Molecular Science and TechnologyAjou UniversitySuwon443‐749Korea
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23
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Schmidt J, Winnerl S, Dimakis E, Hübner R, Schneider H, Helm M. All-THz pump-probe spectroscopy of the intersubband AC-Stark effect in a wide GaAs quantum well. OPTICS EXPRESS 2020; 28:25358-25370. [PMID: 32907058 DOI: 10.1364/oe.398219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
We report the observation of the intersubband AC-Stark effect in a single wide GaAs/AlGaAs quantum well. In a three-level configuration, the n = 2 to n = 3 intersubband transition is resonantly pumped at 3.5 THz using a free-electron laser. The induced spectral changes are probed using THz time-domain spectroscopy with a broadband pulse extending up to 4 THz. We observe an Autler-Townes splitting at the 1 - 2 intersubband transition as well as an indication of a Mollow triplet at the 2 - 3 transition, both evidencing the dressed states. For longer delay times, a relaxation of the hot-electron system with a time constant of around 420 ps is measured.
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24
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Gao H, Schlawin F, Buzzi M, Cavalleri A, Jaksch D. Photoinduced Electron Pairing in a Driven Cavity. PHYSICAL REVIEW LETTERS 2020; 125:053602. [PMID: 32794849 DOI: 10.1103/physrevlett.125.053602] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate how virtual scattering of laser photons inside a cavity via two-photon processes can induce controllable long-range electron interactions in two-dimensional materials. We show that laser light that is red (blue) detuned from the cavity yields attractive (repulsive) interactions whose strength is proportional to the laser intensity. Furthermore, we find that the interactions are not screened effectively except at very low frequencies. For realistic cavity parameters, laser-induced heating of the electrons by inelastic photon scattering is suppressed and coherent electron interactions dominate. When the interactions are attractive, they cause an instability in the Cooper channel at a temperature proportional to the square root of the driving intensity. Our results provide a novel route for engineering electron interactions in a wide range of two-dimensional materials including AB-stacked bilayer graphene and the conducting interface between LaAlO_{3} and SrTiO_{3}.
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Affiliation(s)
- Hongmin Gao
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Frank Schlawin
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Michele Buzzi
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - Andrea Cavalleri
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - Dieter Jaksch
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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25
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Meyer F, Vogel T, Ahmed S, Saraceno CJ. Single-cycle, MHz repetition rate THz source with 66 mW of average power. OPTICS LETTERS 2020; 45:2494-2497. [PMID: 32356799 DOI: 10.1364/ol.386305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/12/2020] [Indexed: 05/28/2023]
Abstract
We demonstrate terahertz (THz) generation using the tilted pulse front method in lithium niobate, driven at an unprecedented high average power of more than 100 W and at a 13.3 MHz repetition rate, provided by a compact amplifier-free mode-locked thin-disk oscillator. The conversion efficiency was optimized with respect to the pump spot size and pump pulse duration, enabling us to generate a maximum THz average power of 66 mW, which is, to the best of our knowledge, the highest reported to date from a laser-driven, few-cycle THz source. Furthermore, we identify beam walk-off as the main obstacle that currently limits the conversion efficiency in this excitation regime (with moderate pulse energies and small spot sizes). Further upscaling to the watt level and beyond is within reach, paving the way for linear and nonlinear high average power THz spectroscopy experiments with an exceptional signal-to-noise ratio at megahertz repetition rates.
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26
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Juraschek DM, Meier QN, Narang P. Parametric Excitation of an Optically Silent Goldstone-Like Phonon Mode. PHYSICAL REVIEW LETTERS 2020; 124:117401. [PMID: 32242728 DOI: 10.1103/physrevlett.124.117401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 01/24/2020] [Accepted: 02/19/2020] [Indexed: 06/11/2023]
Abstract
It has recently been indicated that the hexagonal manganites exhibit Higgs- and Goldstone-like phonon modes that modulate the amplitude and phase of their primary order parameter. Here, we describe a mechanism by which a silent Goldstone-like phonon mode can be coherently excited, which is based on nonlinear coupling to an infrared-active Higgs-like phonon mode. Using a combination of first-principles calculations and phenomenological modeling, we describe the coupled Higgs-Goldstone dynamics in response to the excitation with a terahertz pulse. Besides theoretically demonstrating coherent control of crystallographic Higgs and Goldstone excitations, we show that the previously inaccessible silent phonon modes can be excited coherently with this mechanism.
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Affiliation(s)
- Dominik M Juraschek
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Quintin N Meier
- Department of Materials, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Prineha Narang
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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27
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Novelli F, Guchhait B, Havenith M. Towards Intense THz Spectroscopy on Water: Characterization of Optical Rectification by GaP, OH1, and DSTMS at OPA Wavelengths. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E1311. [PMID: 32183131 PMCID: PMC7143731 DOI: 10.3390/ma13061311] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/05/2020] [Accepted: 03/10/2020] [Indexed: 12/02/2022]
Abstract
Water is the most prominent solvent. The unique properties of water are rooted in the dynamical hydrogen-bonded network. While TeraHertz (THz) radiation can probe directly the collective molecular network, several open issues remain about the interpretation of these highly anharmonic, coupled bands. In order to address this problem, we need intense THz radiation able to drive the liquid into the nonlinear response regime. Firstly, in this study, we summarize the available brilliant THz sources and compare their emission properties. Secondly, we characterize the THz emission by Gallium Phosphide (GaP), 2-{3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene}malononitrile (OH1), and 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium 2,4,6-trimethylbenzenesulfonate (DSTMS) crystals pumped by an amplified near-infrared (NIR) laser with tunable wavelength. We found that both OH1 as well as DSTMS could convert NIR laser radiation between 1200 and 2500 nm into THz radiation with high efficiency (> 2 × 10-4), resulting in THz peak fields exceeding 0.1 MV/cm for modest pump excitation (~ mJ/cm2). DSTMS emits the broadest spectrum, covering the entire bandwidth of our detector from ca. 0.5 to ~7 THz, also at a laser wavelength of 2100 nm. Future improvements will require handling the photothermal damage of these delicate organic crystals, and increasing the THz frequency.
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Affiliation(s)
- Fabio Novelli
- Department of Physical Chemistry II, Ruhr University Bochum, 44801 Bochum, Germany;
| | - Biswajit Guchhait
- Department of Physical Chemistry II, Ruhr University Bochum, 44801 Bochum, Germany;
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Martina Havenith
- Department of Physical Chemistry II, Ruhr University Bochum, 44801 Bochum, Germany;
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28
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Jolly SW, Ahr F, Ravi K, Matlis NH, Kärtner FX, Maier AR. On the effect of third-order dispersion on phase-matched terahertz generation via interfering chirped pulses. OPTICS EXPRESS 2019; 27:34769-34787. [PMID: 31878660 DOI: 10.1364/oe.27.034769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
High-energy narrowband terahertz (THz) pulses, relevant for a plethora of applications, can be created from the interference of two chirped-pulse drive lasers. The presence of third order dispersion, an intrinsic feature of many high-energy drive lasers, however, can significantly reduce the optical-to-THz conversion efficiency and have other undesired effects. Here, we present a detailed description of the effect of third-order dispersion (TOD) in the pump pulse on the generation of THz radiation via phase-matching of broadband highly chirped pulse trains. Although the analysis is general, we focus specifically on parameters typical to a Ti:Sapphire chirped-pulse amplification laser system for quasi-phase-matching in periodically-poled lithium niobate (PPLN) in the range of THz frequencies around 0.5 THz. Our analysis provides the tools to optimize the THz generation process for applications requiring high energy and to control it to produce desired THz waveforms in a variety of scenarios.
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29
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Meyer F, Hekmat N, Vogel T, Omar A, Mansourzadeh S, Fobbe F, Hoffmann M, Wang Y, Saraceno CJ. Milliwatt-class broadband THz source driven by a 112 W, sub-100 fs thin-disk laser. OPTICS EXPRESS 2019; 27:30340-30349. [PMID: 31684282 DOI: 10.1364/oe.27.030340] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate a high repetition-rate, single-cycle THz source with a maximum average power of 1.35 mW, operating at a center frequency of 2 THz. This result was obtained by optical rectification (OR) in GaP using an amplifier-free, nonlinearly compressed modelocked thin-disk oscillator based on Yb:YAG, delivering 8.4 µJ pulses with 88 fs duration at a repetition rate of 13.4 MHz, resulting in driving pulses for OR with 112 W average power and 80 MW peak power. To the best of our knowledge, our result represents the highest average power so far achieved with OR in GaP. The demonstrated performance is very attractive for improving current linear THz time-domain spectroscopy experiments, which are currently restricted by low signal-to-noise ratio and long measurement times.
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30
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Buzzi M, Först M, Cavalleri A. Measuring non-equilibrium dynamics in complex solids with ultrashort X-ray pulses. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20170478. [PMID: 30929635 PMCID: PMC6452049 DOI: 10.1098/rsta.2017.0478] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Strong interactions between electrons give rise to the complexity of quantum materials, which exhibit exotic functional properties and extreme susceptibility to external perturbations. A growing research trend involves the study of these materials away from equilibrium, especially in cases in which the stimulation with optical pulses can coherently enhance cooperative orders. Time-resolved X-ray probes are integral to this type of research, as they can be used to track atomic and electronic structures as they evolve on ultrafast timescales. Here, we review a series of recent experiments where femtosecond X-ray diffraction was used to measure dynamics of complex solids. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.
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Affiliation(s)
- Michele Buzzi
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - Michael Först
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - Andrea Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- Department of Physics, Oxford University, Clarendon Laboratory, Oxford, UK
- e-mail:
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31
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Ingold G, Abela R, Arrell C, Beaud P, Böhler P, Cammarata M, Deng Y, Erny C, Esposito V, Flechsig U, Follath R, Hauri C, Johnson S, Juranic P, Mancini GF, Mankowsky R, Mozzanica A, Oggenfuss RA, Patterson BD, Patthey L, Pedrini B, Rittmann J, Sala L, Savoini M, Svetina C, Zamofing T, Zerdane S, Lemke HT. Experimental station Bernina at SwissFEL: condensed matter physics on femtosecond time scales investigated by X-ray diffraction and spectroscopic methods. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:874-886. [PMID: 31074452 PMCID: PMC6510206 DOI: 10.1107/s160057751900331x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 03/07/2019] [Indexed: 05/22/2023]
Abstract
The Bernina instrument at the SwissFEL Aramis hard X-ray free-electron laser is designed for studying ultrafast phenomena in condensed matter and material science. Ultrashort pulses from an optical laser system covering a large wavelength range can be used to generate specific non-equilibrium states, whose subsequent temporal evolution can be probed by selective X-ray scattering techniques in the range 2-12 keV. For that purpose, the X-ray beamline is equipped with optical elements which tailor the X-ray beam size and energy, as well as with pulse-to-pulse diagnostics that monitor the X-ray pulse intensity, position, as well as its spectral and temporal properties. The experiments can be performed using multiple interchangeable endstations differing in specialization, diffractometer and X-ray analyser configuration and load capacity for specialized sample environment. After testing the instrument in a series of pilot experiments in 2018, regular user operation begins in 2019.
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Affiliation(s)
- Gerhard Ingold
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Rafael Abela
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | | | - Paul Beaud
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Pirmin Böhler
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Marco Cammarata
- Institut de Physique de Rennes, Université de Rennes, 35042 Rennes CEDEX, France
| | - Yunpei Deng
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Christian Erny
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Vincent Esposito
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Uwe Flechsig
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Rolf Follath
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Christoph Hauri
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Steven Johnson
- Institute for Quantum Electronics, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093 Zurich, Switzerland
| | - Pavle Juranic
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | | | - Roman Mankowsky
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Aldo Mozzanica
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | | | | | - Luc Patthey
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Bill Pedrini
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Jochen Rittmann
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Leonardo Sala
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Matteo Savoini
- Institute for Quantum Electronics, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093 Zurich, Switzerland
| | - Cristian Svetina
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Thierry Zamofing
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Serhane Zerdane
- SwissFEL, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
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Abstract
Organic crystals with second-order optical nonlinearity feature very high and ultra-fast optical nonlinearities and are therefore attractive for various photonics applications. During the last decade, they have been found particularly attractive for terahertz (THz) photonics. This is mainly due to the very intense and ultra-broadband THz-wave generation possible with these crystals. We review recent progress and challenges in the development of organic crystalline materials for THz-wave generation and detection applications. We discuss their structure, intrinsic properties, and advantages compared to inorganic alternatives. The characteristic properties of the most widely employed organic crystals at present, such as DAST, DSTMS, OH1, HMQ-TMS, and BNA are analyzed and compared. We summarize the most important principles for THz-wave generation and detection, as well as organic THz-system configurations based on either difference-frequency generation or optical rectification. In addition, we give state-of-the-art examples of very intense and ultra-broadband THz systems that rely on organic crystals. Finally, we present some recent breakthrough demonstrations in nonlinear THz photonics enabled by very intense organic crystalline THz sources, as well as examples of THz spectroscopy and THz imaging using organic crystals as THz sources for various scientific and technological applications.
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Brückner L, Müller N, Motzkus M. Flexible and broadly tunable infrared light source based on shaped sub-10-fs pulses for a multimodal microscopy setup. OPTICS LETTERS 2018; 43:2054-2057. [PMID: 29714744 DOI: 10.1364/ol.43.002054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
We present a versatile approach for mid-infrared spectroscopy through the flexible control of a difference-frequency-generation (DFG) process by femtosecond (fs) pulse shaping and spectral focusing. Based on a broadband sub-10-fs oscillator, the spectral position and spectral resolution can be independently selected within the molecular fingerprint region of more than 2000 cm-1. A spectral resolution better than 20 cm-1 can be achieved, which depends solely on the pulse shaper configuration. An absorption experiment on a polystyrene reference sample finally validates the concept and opens the door for an additional modality in nonlinear multimodal microscopy setups.
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von Hoegen A, Mankowsky R, Fechner M, Först M, Cavalleri A. Probing the interatomic potential of solids with strong-field nonlinear phononics. Nature 2018; 555:79-82. [PMID: 29466328 DOI: 10.1038/nature25484] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 12/04/2017] [Indexed: 01/24/2023]
Abstract
Nonlinear optical techniques at visible frequencies have long been applied to condensed matter spectroscopy. However, because many important excitations of solids are found at low energies, much can be gained from the extension of nonlinear optics to mid-infrared and terahertz frequencies. For example, the nonlinear excitation of lattice vibrations has enabled the dynamic control of material functions. So far it has only been possible to exploit second-order phonon nonlinearities at terahertz field strengths near one million volts per centimetre. Here we achieve an order-of-magnitude increase in field strength and explore higher-order phonon nonlinearities. We excite up to five harmonics of the A1 (transverse optical) phonon mode in the ferroelectric material lithium niobate. By using ultrashort mid-infrared laser pulses to drive the atoms far from their equilibrium positions, and measuring the large-amplitude atomic trajectories, we can sample the interatomic potential of lithium niobate, providing a benchmark for ab initio calculations for the material. Tomography of the energy surface by high-order nonlinear phononics could benefit many aspects of materials research, including the study of classical and quantum phase transitions.
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Affiliation(s)
- A von Hoegen
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - R Mankowsky
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - M Fechner
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany.,Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU, UK
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Lu J, Li X, Zhang Y, Hwang HY, Ofori-Okai BK, Nelson KA. Two-Dimensional Spectroscopy at Terahertz Frequencies. Top Curr Chem (Cham) 2018; 376:6. [DOI: 10.1007/s41061-018-0185-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/05/2018] [Indexed: 10/18/2022]
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Krikunova M, Klimešová E, Kulyk O, Oelze T, Schütte B, Gebert T, Andreasson J. Ultrafast multi-electron dynamics studied with THz-field streaking. EPJ WEB OF CONFERENCES 2018. [DOI: 10.1051/epjconf/201819507003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Hamm P, Meuwly M, Johnson SL, Beaud P, Staub U. Perspective: THz-driven nuclear dynamics from solids to molecules. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:061601. [PMID: 29308420 PMCID: PMC5741436 DOI: 10.1063/1.4992050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
Recent years have seen dramatic developments in the technology of intense pulsed light sources in the THz frequency range. Since many dipole-active excitations in solids and molecules also lie in this range, there is now a tremendous potential to use these light sources to study linear and nonlinear dynamics in such systems. While several experimental investigations of THz-driven dynamics in solid-state systems have demonstrated a variety of interesting linear and nonlinear phenomena, comparatively few efforts have been made to drive analogous dynamics in molecular systems. In the present Perspective article, we discuss the similarities and differences between THz-driven dynamics in solid-state and molecular systems on both conceptual and practical levels. We also discuss the experimental parameters needed for these types of experiments and thereby provide design criteria for a further development of this new research branch. Finally, we present a few recent examples to illustrate the rich physics that may be learned from nonlinear THz excitations of phonons in solids as well as inter-molecular vibrations in liquid and gas-phase systems.
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Affiliation(s)
- Peter Hamm
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Basel, Switzerland
| | - Steve L Johnson
- Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | - Paul Beaud
- Paul Scherrer Institute, Villigen, Switzerland
| | - Urs Staub
- Paul Scherrer Institute, Villigen, Switzerland
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Yang H, Qi J, Pan C, Lu Y, Wu Q, Yao J, Xu J. Efficient generation and frequency modulation of quasi-monochromatic terahertz wave in Lithium Niobate subwavelength waveguide. OPTICS EXPRESS 2017; 25:14766-14773. [PMID: 28789060 DOI: 10.1364/oe.25.014766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 06/15/2017] [Indexed: 06/07/2023]
Abstract
A kind of lateral excitation (LE) configuration is proposed for quasi-monochromatic terahertz generation via impulsive stimulated Raman scattering in a LiNbO3 (LN) slab waveguide by numerical simulation. In an individual waveguide, maximum efficiency frequency-selective excitation is achieved with linewidth narrower than 38 GHz when phase matching is fulfilled between the pump laser and the generated terahertz (THz) waves. As a result, the frequency and linewidth of narrowband THz waves can be tuned through changing the dispersion of THz waves, which is implemented by adjusting the thickness of host LN slab. Furthermore, Au-Air-LN-Air-Au multilayer LE structure is developed to realize a dramatic change of the dispersion to obtain quasi-monochromatic THz waves, of which the linewidth is achieved as narrow as 10 GHz. In addition, the frequency and linewidth of quasi-monochromatic THz waves are modulated dynamically by varying the distance between LN slab and Au mirrors flexibly. Consequently, the optimized LE structure is expected to boost the development of high-precision and real-time inspection and sensing.
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Cartella A, Nova TF, Oriana A, Cerullo G, Först M, Manzoni C, Cavalleri A. Narrowband carrier-envelope phase stable mid-infrared pulses at wavelengths beyond 10 μm by chirped-pulse difference frequency generation. OPTICS LETTERS 2017; 42:663-666. [PMID: 28198834 DOI: 10.1364/ol.42.000663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report on the generation of narrowband carrier-envelope phase stable mid-infrared (MIR) pulses between 10 and 15 μm. High pulse energies and narrow bandwidths are required for the selective nonlinear excitation of collective modes of matter that is not possible with current sources. We demonstrate bandwidths of <2% at 12.5 μm wavelength through difference frequency generation between two near-infrared (NIR) pulses, which are linearly chirped. We obtain a reduction in bandwidth by one order of magnitude, compared to schemes that make use of transform-limited NIR pulses. The wavelength of the narrowband MIR pulse can be tuned by changing the optical delay between the two chirped NIR pulses.
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