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Wu Y, Wang Y, Bao D, Deng X, Zhang S, Yu-Chun L, Ke S, Liu J, Liu Y, Wang Z, Ham P, Hanna A, Pan J, Hu X, Li Z, Zhou J, Wang C. Emerging probing perspective of two-dimensional materials physics: terahertz emission spectroscopy. LIGHT, SCIENCE & APPLICATIONS 2024; 13:146. [PMID: 38951490 PMCID: PMC11217405 DOI: 10.1038/s41377-024-01486-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 04/09/2024] [Accepted: 05/15/2024] [Indexed: 07/03/2024]
Abstract
Terahertz (THz) emission spectroscopy (TES) has emerged as a highly effective and versatile technique for investigating the photoelectric properties of diverse materials and nonlinear physical processes in the past few decades. Concurrently, research on two-dimensional (2D) materials has experienced substantial growth due to their atomically thin structures, exceptional mechanical and optoelectronic properties, and the potential for applications in flexible electronics, sensing, and nanoelectronics. Specifically, these materials offer advantages such as tunable bandgap, high carrier mobility, wideband optical absorption, and relatively short carrier lifetime. By applying TES to investigate the 2D materials, their interfaces and heterostructures, rich information about the interplay among photons, charges, phonons and spins can be unfolded, which provides fundamental understanding for future applications. Thus it is timely to review the nonlinear processes underlying THz emission in 2D materials including optical rectification, photon-drag, high-order harmonic generation and spin-to-charge conversion, showcasing the rich diversity of the TES employed to unravel the complex nature of these materials. Typical applications based on THz emissions, such as THz lasers, ultrafast imaging and biosensors, are also discussed. Step further, we analyzed the unique advantages of spintronic terahertz emitters and the future technological advancements in the development of new THz generation mechanisms leading to advanced THz sources characterized by wide bandwidth, high power and integration, suitable for industrial and commercial applications. The continuous advancement and integration of TES with the study of 2D materials and heterostructures promise to revolutionize research in different areas, including basic materials physics, novel optoelectronic devices, and chips for post-Moore's era.
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Affiliation(s)
- Yifei Wu
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Yuqi Wang
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Di Bao
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Xiaonan Deng
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Simian Zhang
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Lin Yu-Chun
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Shengxian Ke
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Jianing Liu
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Yingjie Liu
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Zeli Wang
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Pingren Ham
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Andrew Hanna
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Jiaming Pan
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Xinyue Hu
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Zhengcao Li
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Ji Zhou
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China
| | - Chen Wang
- State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, 100084, Beijing, China.
- Beijing Advanced Innovation Center for Integrated Circuits, 100084, Beijing, China.
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Isgandarov E, Ropagnol X, Singh M, Ozaki T. Intense terahertz generation from photoconductive antennas. FRONTIERS OF OPTOELECTRONICS 2021; 14:64-93. [PMID: 36637784 PMCID: PMC9743868 DOI: 10.1007/s12200-020-1081-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/16/2020] [Indexed: 06/14/2023]
Abstract
In this paper, we review the past and recent works on generating intense terahertz (THz) pulses from photoconductive antennas (PCAs). We will focus on two types of large-aperture photoconductive antenna (LAPCA) that can generate high-intensity THz pulses (a) those with large-aperture dipoles and (b) those with interdigitated electrodes. We will first describe the principles of THz generation from PCAs. The critical parameters for improving the peak intensity of THz radiation from LAPCAs are summarized. We will then describe the saturation and limitation process of LAPCAs along with the advantages and disadvantages of working with wide-bandgap semiconductor substrates. Then, we will explain the evolution of LAPCA with interdigitated electrodes, which allows one to reduce the photoconductive gap size, and thus obtain higher bias fields while applying lower voltages. We will also describe recent achievements in intense THz pulses generated by interdigitated LAPCAs based on wide-bandgap semiconductors driven by amplified lasers. Finally, we will discuss the future perspectives of THz pulse generation using LAPCAs.
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Affiliation(s)
- Elchin Isgandarov
- Institut National de la Recherche Scientifique, Centre Énergie, Matériaux Télécommunications (INRS-EMT), Varennes, Québec, J3X 1S2, Canada
| | - Xavier Ropagnol
- Institut National de la Recherche Scientifique, Centre Énergie, Matériaux Télécommunications (INRS-EMT), Varennes, Québec, J3X 1S2, Canada
- Département de Génie Électrique, École de Technologie Supérieure (ETS), Montréal, Québec, H3C 1K3, Canada
| | - Mangaljit Singh
- Institut National de la Recherche Scientifique, Centre Énergie, Matériaux Télécommunications (INRS-EMT), Varennes, Québec, J3X 1S2, Canada
| | - Tsuneyuki Ozaki
- Institut National de la Recherche Scientifique, Centre Énergie, Matériaux Télécommunications (INRS-EMT), Varennes, Québec, J3X 1S2, Canada.
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Abstract
Terahertz (THz) radiation occupies part of the electromagnetic spectrum between the infrared and microwave bands. Until recently, technology at THz frequencies was under-developed compared to the rest of the electromagnetic spectrum, leaving a gap between millimeter waves and the far-infrared (FIR). In the past decade, interest in the THz gap has been increased by the development of ultrafast laser-based T-ray systems and their demonstration of diffraction-limited spatial resolution, picosecond temporal resolution, DC-THz spectral bandwidth and signal-to-noise ratios above 104. This chapter reviews the development, the state of the art and the applications of T-ray spectrometers. Continuous-wave (CW) THz-frequency sources and detectors are briefly introduced in comparison to ultrafast pulsed THz systems. An emphasis is placed on experimental applications of T-rays to sensing and imaging, with a view to the continuing advance of technologies and applications in the THz band.
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Affiliation(s)
- S. P. Mickan
- Department of Physics, Applied Physics & Astronomy, and Department of Electrical, Computer & System Engineering, Rensselaer Polytechnic Institute, Troy NY 12180, USA
| | - X.-C. Zhang
- Department of Physics, Applied Physics & Astronomy, and Department of Electrical, Computer & System Engineering, Rensselaer Polytechnic Institute, Troy NY 12180, USA
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Bandyopadhyay A, Stepanov A, Schulkin B, Federici MD, Sengupta A, Gary D, Federici JF, Barat R, Michalopoulou ZH, Zimdars D. Terahertz interferometric and synthetic aperture imaging. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2006; 23:1168-78. [PMID: 16642196 DOI: 10.1364/josaa.23.001168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The stand-off imaging properties of a terahertz (THz) interferometric array are examined. For this application, the imaged object is in the near-field region limit of the imaging array. In this region, spherical and circular array architectures can compensate for near-field distortions and increase the field of view and depth of focus. Imaging of THz point sources is emphasized to demonstrate the imaging method and to compare theoretical predictions to experimental performance.
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Zhang XC. Three-dimensional terahertz wave imaging. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:283-299. [PMID: 15306520 DOI: 10.1098/rsta.2003.1317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Pulsed terahertz (THz) wave sensing and imaging is a coherent measurement technology. Like radar, based on the phase and amplitude of the THz pulse at each frequency, THz waves provide temporal and spectroscopic information that allows us to develop various three-dimensional (3D) terahertz tomographic imaging modalities. The 3D THz tomographic imaging methods we investigated include THz time-of-flight tomography, THz computed tomography (CT) and THz binary lens tomography. THz time-of-flight uses the THz pulses as a probe beam to temporally mark the target, and then constructs a 3D image of the target using the THz waves scattered by the target. THz CT is based on geometrical optics and inspired from X-ray CT. THz binary lens tomography uses the frequency-dependent focal-length property of binary lenses to obtain tomographic images of an object. Three-dimensional THz imaging has potential in such applications as non-destructive inspection. The interaction between a coherent THz pulse and an object provides rich information about the object under study; therefore, 3D THz imaging can be used to inspect or characterize dielectric and semiconductor objects. For example, 3D THz imaging has been used to detect and identify the defects inside a Space Shuttle insulation tile.
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Affiliation(s)
- X-C Zhang
- Center for Terahertz Research, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA.
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