1
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Harris ZB, Xu K, Arbab MH. A handheld polarimetric imaging device and calibration technique for accurate mapping of terahertz Stokes vectors. Sci Rep 2024; 14:17714. [PMID: 39085453 PMCID: PMC11292021 DOI: 10.1038/s41598-024-68530-4] [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: 03/19/2024] [Accepted: 07/24/2024] [Indexed: 08/02/2024] Open
Abstract
In recent years, handheld and portable terahertz instruments have been in rapid development for various applications ranging from non-destructive testing to biomedical imaging and sensing. For instance, we have deployed our Portable Handheld Spectral Reflection (PHASR) Scanners for in vivo full-spectroscopic imaging of skin burns in large animal models in operating room settings. In this paper, we debut the polarimetric version of the PHASR Scanner, and describe a generalized calibration technique to map the spatial and spectral dependence of the Jones matrix of an imaging scanner across its field of view. Our design is based on placement of two orthogonal photoconductive antenna (PCA) detectors separated by a polarizing beam splitter in the PHASR Scanner housing. We show that as few as three independent measurements of a well-characterized polarimetric calibration target are sufficient to determine the polarization state of the incident beam at the sample location, as well as to extract the Jones propagation matrix from the sample location to the detectors. We have tested the accuracy of our scanner by validating polarimetric measurements obtained from a birefringent crystal rotated to various angles, as compared to the theoretically predicted response of the sample. This new version of our PHASR scanner can be used for high-speed imaging and investigation of heterogeneity of polarization-sensitive samples in the field.
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Affiliation(s)
- Zachery B Harris
- Biomedical Engineering Department, Stony Brook University, Stony Brook, NY, USA
| | - Kuangyi Xu
- Biomedical Engineering Department, Stony Brook University, Stony Brook, NY, USA
| | - M Hassan Arbab
- Biomedical Engineering Department, Stony Brook University, Stony Brook, NY, USA.
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2
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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: 12] [Impact Index Per Article: 12.0] [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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3
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Wang S, Qin W, Zhang S, Lou Y, Liu C, Wu T, He Q, Tian C, Zhou L, Wu Y, Tao Z. Nanoengineered Spintronic-Metasurface Terahertz Emitters Enable Beam Steering and Full Polarization Control. NANO LETTERS 2022; 22:10111-10119. [PMID: 36512804 DOI: 10.1021/acs.nanolett.2c03906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The demand for emerging applications at the terahertz frequencies motivates the development of novel and multifunctional devices for the generation and manipulation of terahertz waves. In this work, we report the realization of multifunctional spintronic-metasurface emitters, which allow simultaneous beam-steering and full polarization control over a broadband terahertz beam. This is achieved through engineering individual meta-atoms with nanoscale magnetic heterostructures and, thus, implementing microscopical control over the laser-induced spin and charge dynamics. By arranging the spintronic meta-atoms in the metagrating geometry, the generated terahertz beam can be flexibly steered in space between different orders of diffraction. Furthermore, we demonstrate a simultaneous control over the terahertz polarization states at different emission angles and show that the two control capabilities are mutually independent of each other. The nanoengineered multifunctional terahertz emitter demonstrated in this work can provide a solution to the challenge associated with a growing variety of applications of terahertz technology.
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Affiliation(s)
- Shunjia Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai200433, China
| | - Wentao Qin
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Shanghai Research Center for Quantum Sciences, Fudan University, Shanghai200433, China
| | - Sheng Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai200433, China
| | - Yuchen Lou
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai200433, China
| | - Changqin Liu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Shanghai Research Center for Quantum Sciences, Fudan University, Shanghai200433, China
| | - Tong Wu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Shanghai Research Center for Quantum Sciences, Fudan University, Shanghai200433, China
| | - Qiong He
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai200433, China
| | - Chuanshan Tian
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai200433, China
| | - Lei Zhou
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai200433, China
| | - Yizheng Wu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Shanghai Research Center for Quantum Sciences, Fudan University, Shanghai200433, China
| | - Zhensheng Tao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, China
- Key Laboratory of Micro and Nano Photonic Structures (MOE), Fudan University, Shanghai200433, China
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4
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Chang J, Wang H, Lei Z, Du W, Huang Y, Zhou Y, Zhu L, Xu X. Coherent Elliptically Polarized Terahertz Wave Generation in WSe 2 by Linearly Polarized Femtosecond Laser Excitation. J Phys Chem Lett 2021; 12:10068-10078. [PMID: 34623821 DOI: 10.1021/acs.jpclett.1c02770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Coherent polarization control of terahertz (THz) wave radiation in both the time-domain and the frequency-domain is significant in information technology, material science, and spectroscopic analysis. Elliptically polarized THz radiation is generally limited to chiral materials induced by circularly polarized light excitation. Herein, we demonstrate the coherent elliptically polarized THz radiation from few-layer tungsten diselenide (WSe2) in both the time-domain and the frequency-domain under linearly polarized femtosecond laser excitation. This coherent elliptical THz radiation is mainly dominated by in-plane anisotropic shift current and out-of-plane drift current, which is verified by the THz radiation dependence on the pump laser polarization angles, incident angles, and sample azimuthal angles systematically. The ellipticity and major axis direction of the elliptical THz wave can be efficiently controlled by either pump light polarization or sample azimuthal angle due to the controllable amplitudes and phases of two coherent orthogonal THz wave components. Our finding provides a method to distinguish drift and shift photocurrents in different directions and offers a unique design concept for elliptical THz generation with two-dimensional (2D) material physics.
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Affiliation(s)
- Jiawei Chang
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Xi'an 710069, China
| | - He Wang
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Xi'an 710069, China
| | - Zhen Lei
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Xi'an 710069, China
| | - Wanyi Du
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Xi'an 710069, China
| | - Yuanyuan Huang
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Xi'an 710069, China
| | - Yixuan Zhou
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Xi'an 710069, China
| | - Lipeng Zhu
- School of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
| | - Xinlong Xu
- Shaanxi Joint Lab of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, Xi'an 710069, China
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5
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Song Q, Yuan X, Hu S, Huang J, Zhong H, Lin Q, Wang H, Lu X, Zheng M, Cai Y, Zeng X, Xu S. Enhance terahertz radiation and its polarization- control with two paralleled filaments pumped by two-color femtosecond laser fields. OPTICS EXPRESS 2021; 29:22659-22666. [PMID: 34266024 DOI: 10.1364/oe.427896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
We present experimentally an obvious enhancement of the terahertz (THz) radiation with two paralleled filaments pumped by two-color laser fields for a full use of a high laser power, compared with single filament. By mapping the 3-dimensional electric trajectories of generated THz fields with a (111) ZnTe crystal, we observe that the total THz polarization from two filaments can be manipulated by varying the time delay between the two orthogonally polarized pumps, which agrees well with the simulations under the photocurrent model. Notably, the power and spectrum of the THz field almost keep unchanged while manipulating the ellipticity of the THz polarization, which is important for a polarization-controllable THz source.
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6
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Bogatskaya AV, Gnezdovskaia NE, Popov AM. Circularly polarized terahertz pulse generation in a plasma channel created by a uv high-intense laser pulse in the presence of a static magnetic field. Phys Rev E 2020; 102:043202. [PMID: 33212635 DOI: 10.1103/physreve.102.043202] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/11/2020] [Indexed: 11/07/2022]
Abstract
This paper is devoted to the problem of obtaining high-intense circularly polarized terahertz radiation in a nonequilibrium xenon plasma channel in the presence of an external static magnetic field. The physical mechanism is based on the well-known cyclotron resonance effect which enables to provide effective plasma-electromagnetic wave interaction that can increase the gain in plasma proposed earlier by the authors. According to the suggested scheme, a static magnetic field is imposed on a gas target along the propagation direction of a femtosecond ultraviolet laser driver. Numerical simulations demonstrate that, by varying a magnetic field, one can control the range of amplified frequencies in plasmas at atmospheric and lower pressures. Moreover, a pressure decrease in the nonequilibrium rare gas plasma channel allows one to obtain a larger value of the gain factor. Thus, controlling the central frequency and bandwidth of the amplified terahertz signals leads to producing both ultrashort and rather long high-intense pulses at the output of nonequilibrium plasma channel.
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Affiliation(s)
- A V Bogatskaya
- D. V. Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia.,Department of Physics, Moscow State University, 119991 Moscow, Russia.,P. N. Lebedev Physical Institute, RAS, Moscow, Russia
| | - N E Gnezdovskaia
- Department of Physics, Moscow State University, 119991 Moscow, Russia
| | - A M Popov
- D. V. Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia.,Department of Physics, Moscow State University, 119991 Moscow, Russia.,P. N. Lebedev Physical Institute, RAS, Moscow, Russia
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7
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Tunable THz Pulses Generation in Non-Equilibrium Magnetized Plasma: The Role of Plasma Kinetics. PHOTONICS 2020. [DOI: 10.3390/photonics7040082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this paper the theoretical model to consider the influence of kinetic properties of nonequilibrium two-color plasma during the THz pulses generation in the presence of static magnetic field is developed. It is shown that applying a static magnetic field on a gas along the direction of propagation of an ionizing two-color laser pulse allows one to produce two-frequency emissions in THz range with tunable central frequency and bandwidth, which are strongly dependent on electron velocity distribution function (EVDF) formed in the plasma as well as relations between collisional, plasma and cyclotron frequencies.
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8
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Stokes-Mueller method for comprehensive characterization of coherent terahertz waves. Sci Rep 2020; 10:15426. [PMID: 32963295 PMCID: PMC7508837 DOI: 10.1038/s41598-020-72049-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/14/2020] [Indexed: 11/08/2022] Open
Abstract
Ideally, the full characterization of coherent terahertz (THz) pulses would provide information on the amplitude and direction of its THz electric field, in space and in time, with unlimited dynamic range. Here, we propose and demonstrate a new approach based on the Stokes–Mueller formalism. Our approach can measure the full temporal and spatial variation of coherent THz fields, as well as its polarization state with a high dynamic range. This method employs a simple configuration, using a polarization state analyzer after the electro-optic sampling crystal. This technique could allow high sensitivity due to its ability to use thick detection crystals, which also would lead to improved spectral resolution by allowing longer scans in the time domain.
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9
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Shu XF, Yu CX, Liu J. Enhanced terahertz radiation by an intense femtosecond laser field assisted with sub-cycle pulses. OPTICS EXPRESS 2019; 27:7751-7761. [PMID: 30876333 DOI: 10.1364/oe.27.007751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
In this work, we theoretically investigate the enhanced Terahertz (THz) radiation by an intense laser pulse assisted with sub-cycle pulses (SCP) in the framework of quantum theory. By numerically solving the Schrödinger equation, the production and the dynamics of ionized electrons are analyzed. The simulations show that the SCP plays different roles for different time delays in the generation of THz radiation, such as increasing the production of the ionized electrons and manipulating their trajectories. The time-frequency analysis of the THz radiation is also carried out, which indicates that the THz radiation mainly occurs where the SCP is launched, and the THz radiation mainly comes from the formation of the asymmetric electric current. Finally, the scheme of dual sub-cycle pulses is studied, and we find that the THz radiations can constructively or destructively interfere, which leads to the formation of the streaky structures of radiation spectra.
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Nagai M, Mukai N, Minowa Y, Ashida M, Suzuki T, Takayanagi J, Ohtake H. Achromatic wave plate in THz frequency region based on parallel metal plate waveguides with a pillar array. OPTICS EXPRESS 2015; 23:4641-4649. [PMID: 25836501 DOI: 10.1364/oe.23.004641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrated an achromatic wave plate based on parallel metal plate waveguides in the high THz frequency region. The metal plates have periodic rough structures on the surface, which allow slow transverse magnetic wave propagation and fast transverse electric wave propagation. A numerical simulation showed that the height of the periodic roughness is important for optimizing the birefringence. We fabricated stacked metal plates containing two types of structures by chemical etching. An array of small pillars on the metal plates allows higher frequency optimization. We experimentally demonstrated an achromatic quarter-wave plate in the frequency region from 2.0 to 3.1 THz.
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11
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Manipulation of the polarization of Terahertz wave in subwavelength regime. Sci Rep 2015; 5:8306. [PMID: 25655196 PMCID: PMC4319153 DOI: 10.1038/srep08306] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 12/22/2014] [Indexed: 11/08/2022] Open
Abstract
By generalizing the concept of spoof surface Plasmons (Science 305, 847), we analytically demonstrate that subwavelength quarter-wave and half-wave plates can be realized in a metal hole array (MHA) sandwiched by two thin-layer materials, whose optical responses can be characterized by their optical conductivities. These abilities of polarization conversion can be attributed to the novel eigenstates induced by the hybridization of the spoof surface plamsons with the current generated in the thin-layer. Due to this mechanism, the robustness of the system is promised. The analytic predictions are verified numerically by modeling the thin-layer material as an experimentally feasible topological-insulator/SiO2 multilayer. Moreover, the possibility of extending the principle to a broad range of materials is dicussed.
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12
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Kawada Y, Yasuda T, Nakanishi A, Akiyama K, Hakamata K, Takahashi H. Achromatic prism-type wave plate for broadband terahertz pulses. OPTICS LETTERS 2014; 39:2794-2797. [PMID: 24784105 DOI: 10.1364/ol.39.002794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrated achromatic half- and quarter-wave plates for broadband terahertz pulses using phase retardation by internal total reflection. Prism-type wave plates realized ultra-broadband retardation stability up to 2.5 THz, which was the limitation of our experimental setup. Novel aspects of our work were use of a 3λ/4 plate as a quarter-wave plate and a multistacked prism-type (MSP) wave plate for a large-aperture THz beam. Real-time polarization imaging of two crossed bunches of hairs was performed to show the efficiency of the MSP wave plate. We clearly observed polarization dependence of the hair direction.
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13
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Nagai M, Mukai N, Minowa Y, Ashida M, Takayanagi J, Ohtake H. Achromatic THz wave plate composed of stacked parallel metal plates. OPTICS LETTERS 2014; 39:146-149. [PMID: 24365844 DOI: 10.1364/ol.39.000146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We propose a simple achromatic terahertz wave plate composed of stacked parallel metal plates with a hole array. It consists of an ensemble of designed parallel plate waveguides; the high and low propagation speeds of waves in TE and TM waveguide modes with the same group velocity cause a constant phase difference over a wide frequency region. Using that wave plate, we obtained intense single- and multi-cycle THz pulses with circular polarization.
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14
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Arikawa T, Wang X, Belyanin AA, Kono J. Giant tunable Faraday effect in a semiconductor magneto-plasma for broadband terahertz polarization optics. OPTICS EXPRESS 2012; 20:19484-19492. [PMID: 23038591 DOI: 10.1364/oe.20.019484] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on a giant Faraday effect in an electron plasma in n-InSb probed via polarization-resolved terahertz (THz) time-domain spectroscopy. Polarization rotation angles and ellipticities reach as large as π/2 and 1, respectively, over a wide frequency range (0.3-2.5 THz) at magnetic fields of a few Tesla. The experimental results together with theoretical simulations show its promising ability to construct broadband and tunable THz polarization optics, such as a circular polarizer, half-wave plate, and polarization modulators.
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Affiliation(s)
- Takashi Arikawa
- Department of Electrical & Computer Engineering, Rice University, Houston, Texas 77005, USA
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15
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Lee K, Yi M, Song JD, Ahn J. Polarization shaping of few-cycle terahertz waves. OPTICS EXPRESS 2012; 20:12463-12472. [PMID: 22714234 DOI: 10.1364/oe.20.012463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a polarization shaping technique for few-cycle terahertz (THz) waves. For this, N femtosecond laser pulses are generated from a devised diffractive optical system made of as-many glass wedges, which then simultaneously illuminate on various angular positions of a sub-wavelength circular pattern of an indium arsenide thin film, to produce a THz wave of tailor-made polarization state given as a superposition of N linearly-polarized THz pulses. By properly arranging the orientation and thickness of the glass wedges, which determine the polarization and its timing of the constituent THz pulses, we successfully generate THz waves of various unconventional polarization states, such as polarization rotation and alternation between circular polarization states.
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Affiliation(s)
- Kanghee Lee
- Department of Physics, KAIST, Daejeon 305-701, Korea
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16
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Morris CM, Aguilar RV, Stier AV, Armitage NP. Polarization modulation time-domain terahertz polarimetry. OPTICS EXPRESS 2012; 20:12303-12317. [PMID: 22714218 DOI: 10.1364/oe.20.012303] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present high precision measurements of polarization rotations in the frequency range from 0.1 to 2.5 THz using a polarization modulation technique. A motorized stage rotates a polarizer at ~ 80 Hz, and the resulting modulation of the polarization is measured by a lock-in technique. We achieve an accuracy of 0.050° (900 μrad) and a precision of 0.02° (350 μrad) for small rotation angles. A detailed mathematical description of the technique is presented, showing its ability to fully characterize elliptical polarizations from 0.1 to 2.5 THz.
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Affiliation(s)
- C M Morris
- Department of Physics and Astronomy, The Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland 21218, USA
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17
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Lu X, Zhang XC. Generation of elliptically polarized terahertz waves from laser-induced plasma with double helix electrodes. PHYSICAL REVIEW LETTERS 2012; 108:123903. [PMID: 22540584 DOI: 10.1103/physrevlett.108.123903] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Indexed: 05/31/2023]
Abstract
By applying a helical electric field along a plasma region, a revolving electron current is formed along the plasma and an elliptically polarized far-field terahertz wave pattern is observed. The observed terahertz wave polarization reveals the remarkable role of velocity retardation between optical pulses and generated terahertz pulses in the generation process. Extensive simulations, including longitudinal propagation effects, are performed to clarify the mechanisms responsible for polarization control of air-plasma-based terahertz sources.
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Affiliation(s)
- Xiaofei Lu
- Department of Physics, Applied Physics, and Astronomy, Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
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