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Ponomarev DS, Lavrukhin DV, Zenchenko NV, Frolov TV, Glinskiy IA, Khabibullin RA, Katyba GM, Kurlov VN, Otsuji T, Zaytsev KI. Boosting photoconductive large-area THz emitter via optical light confinement behind a highly refractive sapphire-fiber lens. OPTICS LETTERS 2022; 47:1899-1902. [PMID: 35363764 DOI: 10.1364/ol.452192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/16/2022] [Indexed: 05/27/2023]
Abstract
We report on a sapphire-fiber-based lens that can be used to enhance the emitted THz power of a large-area photoconductive antenna (PCA). Using numerical simulations, we demonstrate that the lens provides a spatial redistribution of the photocarriers density in the PCA's gap. By optimizing the diameter of the sapphire-fiber, one could reach efficient confinement of the photocarriers in the vicinity of the PCA electrodes with a 10-μm gap size for a 220-μm-thick sapphire-fiber. This allows enhancing the coupling of the incident electromagnetic waves at the interface between the sapphire fiber and the semiconductor with the antenna terminals by ∼40 times for a single PCA element, as well as boosting the total efficiency of the large-area PCA-emitter up to ∼7-10 times. To validate our approach, we propose a step-by-step process that can be used for the precise and controllable placement of the sapphire-fiber on the surface of a single PCA.
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Ikamas K, Nevinskas I, Krotkus A, Lisauskas A. Silicon Field Effect Transistor as the Nonlinear Detector for Terahertz Autocorellators. SENSORS 2018; 18:s18113735. [PMID: 30400183 PMCID: PMC6263913 DOI: 10.3390/s18113735] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 10/28/2018] [Accepted: 10/31/2018] [Indexed: 11/18/2022]
Abstract
We demonstrate that the rectifying field effect transistor, biased to the subthreshold regime, in a large signal regime exhibits a super-linear response to the incident terahertz (THz) power. This phenomenon can be exploited in a variety of experiments which exploit a nonlinear response, such as nonlinear autocorrelation measurements, for direct assessment of intrinsic response time using a pump-probe configuration or for indirect calibration of the oscillating voltage amplitude, which is delivered to the device. For these purposes, we employ a broadband bow-tie antenna coupled Si CMOS field-effect-transistor-based THz detector (TeraFET) in a nonlinear autocorrelation experiment performed with picoseconds-scale pulsed THz radiation. We have found that, in a wide range of gate bias (above the threshold voltage Vth=445 mV), the detected signal follows linearly to the emitted THz power. For gate bias below the threshold voltage (at 350 mV and below), the detected signal increases in a super-linear manner. A combination of these response regimes allows for performing nonlinear autocorrelation measurements with a single device and avoiding cryogenic cooling.
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Affiliation(s)
- Kęstutis Ikamas
- Institute of Applied Electrodynamics and Telecommunications, Vilnius University, Sauletekio av. 3, LT-10257 Vilnius, Lithuania.
- The General Jonas Žemaitis Military Academy of Lithuania, Šilo str. 5A, LT-10322 Vilnius, Lithuania.
| | - Ignas Nevinskas
- Center For Physical Sciences And Technology, Sauletekio av. 3, LT-10257 Vilnius, Lithuania.
| | - Arūnas Krotkus
- Center For Physical Sciences And Technology, Sauletekio av. 3, LT-10257 Vilnius, Lithuania.
| | - Alvydas Lisauskas
- Institute of Applied Electrodynamics and Telecommunications, Vilnius University, Sauletekio av. 3, LT-10257 Vilnius, Lithuania.
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Mittendorff M, Suess RJ, Leong E, Murphy TE. Optical Gating of Black Phosphorus for Terahertz Detection. NANO LETTERS 2017; 17:5811-5816. [PMID: 28820599 DOI: 10.1021/acs.nanolett.7b02931] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoconductive antennas are widely used for time-resolved detection of terahertz (THz) pulses. In contrast to photothermoelectric or bolometric THz detection, the coherent detection allows direct measurement of the electric field transient of a THz pulse, which contains both spectral and phase information. In this Letter, we demonstrate for the first time photoconductive detection of free-space propagating THz radiation with thin flakes of a van der Waals material. Mechanically exfoliated flakes of black phosphorus are combined with an antenna that concentrates the THz fields to the small flake (∼10 μm). Similar performance is reached at gating wavelengths of 800 and 1550 nm, which suggests that the narrow bandgap of black phosphorus could allow operation at wavelengths as long as 4 μm. The detected spectrum peaks at 60 GHz, where the signal-to-noise ratio is of the order of 40 dB, and the detectable signal extends to 0.2 THz. The measured signal strongly depends on the polarization of the THz field and the gating pulse, which is explained by the role of the antenna and the anisotropy of the black phosphorus flake, respectively. We analyze the limitations of the device and show potential improvements that could significantly increase the efficiency and bandwidth.
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Affiliation(s)
- Martin Mittendorff
- Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, Maryland 20740, United States
| | - Ryan J Suess
- Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, Maryland 20740, United States
- Department of Electrical and Computer Engineering, University of Maryland , College Park, Maryland 20740, United States
| | - Edward Leong
- Department of Electrical and Computer Engineering, University of Maryland , College Park, Maryland 20740, United States
| | - Thomas E Murphy
- Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, Maryland 20740, United States
- Department of Electrical and Computer Engineering, University of Maryland , College Park, Maryland 20740, United States
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Jooshesh A, Fesharaki F, Bahrami-Yekta V, Mahtab M, Tiedje T, Darcie TE, Gordon R. Plasmon-enhanced LT-GaAs/AlAs heterostructure photoconductive antennas for sub-bandgap terahertz generation. OPTICS EXPRESS 2017; 25:22140-22148. [PMID: 29041502 DOI: 10.1364/oe.25.022140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Photocurrent generation in low-temperature-grown GaAs (LT-GaAs) has been significantly improved by growing a thin AlAs isolation layer between the LT-GaAs layer and semi-insulating (SI)-GaAs substrate. The AlAs layer allows greater arsenic incorporation into the LT-GaAs layer, prevents current diffusion into the GaAs substrate, and provides optical back-reflection that enhances below bandgap terahertz generation. Our plasmon-enhanced LT-GaAs/AlAs photoconductive antennas provide 4.5 THz bandwidth and 75 dB signal-to-noise ratio (SNR) under 50 mW of 1570 nm excitation, whereas the structure without the AlAs layer gives 3 THz bandwidth, 65 dB SNR for the same conditions.
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Lai W, Mazin Abdulmunem O, del Pino P, Pelaz B, Parak WJ, Zhang Q, Zhang H. Enhanced Terahertz Radiation Generation of Photoconductive Antennas Based on Manganese Ferrite Nanoparticles. Sci Rep 2017; 7:46261. [PMID: 28393855 PMCID: PMC5385867 DOI: 10.1038/srep46261] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/13/2017] [Indexed: 11/18/2022] Open
Abstract
This paper presents a significant effect of manganese ferrite nanoparticles (MnFe2O4 NPs) on the increase of the surface photoconductivity of semiconductors. Herein, the optical characterization of photo-excited carriers of silicon coated with MnFe2O4 NPs was studied by using THz time-domain spectroscopy (THz-TDs). We observed that silicon coated with MnFe2O4 NPs provided a significantly enhanced attenuation of THz radiation in comparison with bare silicon substrates under laser irradiation. The experimental results were assessed in the context of a surface band structure model of semiconductors. In addition, photoconductive antennas coated with MnFe2O4 NPs significantly improved the efficiency of THz radiation generation and signal to noise ratio of the THz signal. This work demonstrates that coating with MnFe2O4 NPs could improve the overall performance of THz systems, and MnFe2O4 NPs could be further used for the implementation of novel optical devices.
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Affiliation(s)
- Weien Lai
- Academy of Photoelectric Technology, HeFei University of Technology, HeFei, 230009, China
- Faculty of Physics, Philipps-Universität Marburg, Renthof 7, Marburg, 35032, Germany
| | - Oday Mazin Abdulmunem
- Faculty of Physics, Philipps-Universität Marburg, Renthof 7, Marburg, 35032, Germany
| | - Pablo del Pino
- Centro Singular de Investigación en Química Biológica e Materiales Moleculares (CiQUS), and Departamento de Física de Partículas, Universidade de Santiago de Compostela, Santiago de Compostela, 15782, Spain
| | - Beatriz Pelaz
- Centro Singular de Investigación en Química Biológica e Materiales Moleculares (CiQUS), and Departamento de Física de Partículas, Universidade de Santiago de Compostela, Santiago de Compostela, 15782, Spain
| | - Wolfgang J. Parak
- Faculty of Physics, Philipps-Universität Marburg, Renthof 7, Marburg, 35032, Germany
- Institute of Nano Biomedicine and Engineering, Key Laboratory for Thin Film and Microfabrication Technology of the Ministry of Education, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, 800 Dongchuan RD, Shanghai, 200240, China
| | - Qian Zhang
- Faculty of Physics, Philipps-Universität Marburg, Renthof 7, Marburg, 35032, Germany
- Institute of Nano Biomedicine and Engineering, Key Laboratory for Thin Film and Microfabrication Technology of the Ministry of Education, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, 800 Dongchuan RD, Shanghai, 200240, China
| | - Huaiwu Zhang
- State Key Laboratory of Electronic Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
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Zhang Y, Zhang X, Li S, Gu J, Li Y, Tian Z, Ouyang C, He M, Han J, Zhang W. A Broadband THz-TDS System Based on DSTMS Emitter and LTG InGaAs/InAlAs Photoconductive Antenna Detector. Sci Rep 2016; 6:26949. [PMID: 27244689 PMCID: PMC4886634 DOI: 10.1038/srep26949] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/11/2016] [Indexed: 11/08/2022] Open
Abstract
We demonstrate a 4-f terahertz time-domain spectroscopy (THz-TDS) system using an organic crystal DSTMS as the THz emitter and a low temperature grown (LTG) InGaAs/InAlAs photoconductive antenna as the receiver. The system covers a frequency range from 0.2 up to 8 THz. The influences of the pump laser power, the probe laser power and the azimuthal angle of the DSTMS crystal on the time-domain THz amplitude are experimentally analyzed. The frequency accuracy of the system is verified by measuring two metamaterial samples and a lactose film in this THz-TDS system. The proposed combination of DSTMS emission and PC antenna detection realizes a compact and low-cost THz-TDS scheme with an ultra-broad bandwidth, which may promote the development and the applications of THz-TDS techniques.
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Affiliation(s)
- Ying Zhang
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Xiaoling Zhang
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Shaoxian Li
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Jianqiang Gu
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Yanfeng Li
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Zhen Tian
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Chunmei Ouyang
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Mingxia He
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Jiaguang Han
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
| | - Weili Zhang
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, and Key Laboratory of Optoelectronics Information and Technology, Ministry of Education of China, Tianjin 300072, People’s Republic of China
- School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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Photoconductive terahertz generation from textured semiconductor materials. Sci Rep 2016; 6:23185. [PMID: 26979292 PMCID: PMC4793249 DOI: 10.1038/srep23185] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 03/01/2016] [Indexed: 11/29/2022] Open
Abstract
Photoconductive (PC) terahertz (THz) emitters are often limited by ohmic loss and Joule heating—as these effects can lead to thermal runaway and premature device breakdown. To address this, the proposed work introduces PC THz emitters based on textured InP materials. The enhanced surface recombination and decreased charge-carrier lifetimes of the textured InP materials reduce residual photocurrents, following the picosecond THz waveform generation, and this diminishes Joule heating in the emitters. A non-textured InP material is used as a baseline for studies of fine- and coarse-textured InP materials. Ultrafast pump-probe and THz setups are used to measure the charge-carrier lifetimes and THz response/photocurrent consumption of the respective materials and emitters. It is found that similar temporal and spectral characteristics can be achieved with the THz emitters, but the level of photocurrent consumption (yielding Joule heating) is greatly reduced in the textured materials.
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Jooshesh A, Bahrami-Yekta V, Zhang J, Tiedje T, Darcie TE, Gordon R. Plasmon-Enhanced below Bandgap Photoconductive Terahertz Generation and Detection. NANO LETTERS 2015; 15:8306-8310. [PMID: 26575274 DOI: 10.1021/acs.nanolett.5b03922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We use plasmon enhancement to achieve terahertz (THz) photoconductive switches that combine the benefits of low-temperature grown GaAs with mature 1.5 μm femtosecond lasers operating below the bandgap. These below bandgap plasmon-enhanced photoconductive receivers and sources significantly outperform commercial devices based on InGaAs, both in terms of bandwidth and power, even though they operate well below saturation. This paves the way for high-performance low-cost portable systems to enable emerging THz applications in spectroscopy, security, medical imaging, and communication.
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Affiliation(s)
- Afshin Jooshesh
- Department of Electrical and Computer Engineering, University of Victoria , Victoria, British Columbia V8P 5C2, Canada
| | - Vahid Bahrami-Yekta
- Department of Electrical and Computer Engineering, University of Victoria , Victoria, British Columbia V8P 5C2, Canada
| | - Jinye Zhang
- Department of Electrical and Computer Engineering, University of Victoria , Victoria, British Columbia V8P 5C2, Canada
| | - Thomas Tiedje
- Department of Electrical and Computer Engineering, University of Victoria , Victoria, British Columbia V8P 5C2, Canada
| | - Thomas E Darcie
- Department of Electrical and Computer Engineering, University of Victoria , Victoria, British Columbia V8P 5C2, Canada
| | - Reuven Gordon
- Department of Electrical and Computer Engineering, University of Victoria , Victoria, British Columbia V8P 5C2, Canada
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Jooshesh A, Smith L, Masnadi-Shirazi M, Bahrami-Yekta V, Tiedje T, Darcie TE, Gordon R. Nanoplasmonics enhanced terahertz sources. OPTICS EXPRESS 2014; 22:27992-28001. [PMID: 25402040 DOI: 10.1364/oe.22.027992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Arrayed hexagonal metal nanostructures are used to maximize the local current density while providing effective thermal management at the nanoscale, thereby allowing for increased emission from photoconductive terahertz (THz) sources. The THz emission field amplitude was increased by 60% above that of a commercial THz photoconductive antenna, even though the hexagonal nanostructured device had 75% of the bias voltage. The arrayed hexagonal outperforms our previously investigated strip array nanoplasmonic structure by providing stronger localization of the current density near the metal surface with an operating bandwidth of 2.6 THz. This approach is promising to achieve efficient THz sources.
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