Abstract-Plasmonic semiconductor nanogroove array enhanced broad spectral band millimetre and terahertz wave detection

 

Jinchao Tong, Fei Suo, Tianning Zhang, Zhiming Huang, Junhao Chu, Dao Hua Zhang

https://www.nature.com/articles/s41377-021-00505-w

High-performance uncooled millimetre and terahertz wave detectors are required as a building block for a wide range of applications. The state-of-the-art technologies, however, are plagued by low sensitivity, narrow spectral bandwidth, and complicated architecture. Here, we report semiconductor surface plasmon enhanced high-performance broadband millimetre and terahertz wave detectors which are based on nanogroove InSb array epitaxially grown on GaAs substrate for room temperature operation. By making a nanogroove array in the grown InSb layer, strong millimetre and terahertz wave surface plasmon polaritons can be generated at the InSb–air interfaces, which results in significant improvement in detecting performance. A noise equivalent power (NEP) of 2.2 × 10−14 W Hz−1/2 or a detectivity (D*) of 2.7 × 1012 cm Hz1/2 W−1 at 1.75 mm (0.171 THz) is achieved at room temperature. By lowering the temperature to the thermoelectric cooling available 200 K, the corresponding NEP and D* of the nanogroove device can be improved to 3.8 × 10−15 W Hz−1/2 and 1.6 × 1013 cm Hz1/2 W−1, respectively. In addition, such a single device can perform broad spectral band detection from 0.9 mm (0.330 THz) to 9.4 mm (0.032 THz). Fast responses of 3.5 µs and 780 ns are achieved at room temperature and 200 K, respectively. Such high-performance millimetre and terahertz wave photodetectors are useful for wide applications such as high capacity communications, walk-through security, biological diagnosis, spectroscopy, and remote sensing. In addition, the integration of plasmonic semiconductor nanostructures paves a way for realizing high performance and multifunctional long-wavelength optoelectrical devices.

Abstract-Properties of BIBO crystal in the terahertz regime

Nazar Nikolaev,  Zhiming Huang,  Jingguo Huang,  Yang Li,  Yury Andreev, Grigory Lanskii

https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11348/1134818/Properties-of-BIBO-crystal-in-the-terahertz-regime-Conference-Presentation/10.1117/12.2555663.full?SSO=1

In recent years, the terahertz sources have attracted much attention for its special use compared with so for UV-visible range. Crystal with high quality and special properties is their indispensable part. Optical properties such as the absorption coefficient and refractive index at three basic crystal orientations (x, y, and z-direction) of the BIBO crystal have been studied by the Terahertz Time-Domain Spectroscopy at room temperature. A large birefringence was observed. The measured refractive index components were approximated in the form of Sellmeier equations. Phase-matching curves for collinear down-conversion of IR laser frequencies into the THz domain were preliminarily estimated. A prospect of BIBO crystals as THz generators are discussed, and comparison with popular crystals is given.

Abstract-High efficient terahertz generation from cryogenic gallium phosphide based on collinear difference frequency

Jingguo Huang, Yang Li, Yanqing Gao, Gaofang Li, Zhiming Huang, Junhao Chu, Yury Andreev

https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11046/1104631/High-efficient-terahertz-generation-from-cryogenic-gallium-phosphide-based-on/10.1117/12.2524100.short?SSO=1

In this paper, a high efficient terahertz source based on n-type gallium phosphide crystal via cryogenic process is investigated through collinear difference frequency generation pumper by 1064 nm Nd:YAG laser and its OPO system. Absorption coefficient of this crystal at THz range shows a dramatic decrease from ~ 50 cm^-1 to 0.5 cm-^-1 as the temperature decreases from 300 k to 80 k. Four times enhancement of the terahertz emission power and much more broad spectra range (~ 0.2- 3.8 THz) has been achieved in this kind of 0.5 mm length gallium phosphide crystal during the whole varied temperature difference frequency generation from 300 k to 80 k. These results indicate that cooling down the crystal temperature is an effective way to improve the terahertz source property, such as terahertz output power and frequency range.

© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Abstract-Silicon-based high sensitivity of room-temperature microwave and sub-terahertz detector

Applied Physics Express

Caiyang Wu, Wei Zhou, Niangjuan Yao, Xinyue Xu, Yue Qu, Zhibo Zhang, Jing Wu, Lin Jiang, Zhiming Huang, Junhao Chu

https://iopscience.iop.org/article/10.7567/1882-0786/ab14fc

We demonstrated a Si-based photoelectric detector with silicon-on-insulator material. The Si-based detector was successfully fabricated and showed broadband response from 20-40 GHz to 0.165-0.173 THz radiation at room temperature. It achieved a responsivity of 49.3 kV/W and NEP of 0.38 pW/√Hz at 20-40 GHz, and achieved a responsivity of 3.3 kV/W and NEP of 5.7 pW/√Hz at 0.165-0.173 THz; Moreover, a short response time 810 ns was realized for the detector. The simple structure, excellent performance and easy integration of the detectors, which provides an avenue to the optoelectronic integration of sensitive room-temperature terahertz focal-plane arrays.

Abstract-Terahertz communication windows and their point-to-point transmission verification

Zhenyang Xiao, Qiujie Yang, Jingguo Huang, Zhiming Huang, Wei Zhou, Yanqing Gao, Rong Shu, and Zhiping He

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-57-27-7673

Terahertz communication is recognized as a transformational technology that can meet the future demands of point-to-point communication. The study of terahertz atmospheric transmission characteristics is important for guiding the terahertz communication window selection process. In this report, based on the modified ITU-R P.676-10 model, we determined that the terahertz communication windows above 100 GHz were located at the bands at approximately 140, 220, 340, 410, and 460 GHz, which is verified by recent experiments. We also verified the feasibility of indoor point-to-point communication by the 110 m transmission experiment through the communication window around 460 GHz.

© 2018 Optical Society of America

Abstract-Terahertz Detection: Extreme Sensitivity of Room-Temperature Photoelectric Effect for Terahertz Detection

http://onlinelibrary.wiley.com/doi/10.1002/adma.201670005/full

Terahertz (THz) is the gap between infrared and microwave frequencies. THz detection is still a formidable challenge even though no suitable theory has been built until now, although considerable mechanisms have been proposed. On page 112, Z. Huang and co-workers propose a unique theory to realize an excellent photoelectric effect and experimentally demonstrate its extreme sensitivity to room-temperature THz detection.

Abstract-Extreme Sensitivity of Room-Temperature Photoelectric Effect for Terahertz Detection

http://onlinelibrary.wiley.com/doi/10.1002/adma.201503350/full

Extreme sensitivity of room-temperature photoelectric effect for terahertz (THz) detection is demonstrated by generating extra carriers in an electromagnetic induced well located at the semiconductor using a wrapped metal–semiconductor–metal configuration. The excellent performance achieved with THz detectors shows great potential to open avenues for THz detection.