1 东华大学 理学院 应用物理系，上海 201620
2 中国科学院上海技术物理研究所 红外物理国家重点实验室，上海 200083
3 上海智能电子与系统研究所，上海 201620
4 中国科学院大学，北京 100049
基于二维拓扑绝缘体Bi2Te3材料利用微纳工艺制备了金属-拓扑绝缘体-金属(MTM)结构的太赫兹光电探测器.器件在0.022 THz的响应率可达2×103 A/W，噪声等效功率(NEP)低于7.5×10-15 W/Hz1/2，探测率D*高于1.62 ×1011 cm·Hz1/2/W；在0.166 THz的响应率可达281.6 A/W，NEP低于5.18×10-14 W/Hz1/2，D*高于2.2×1010 cm·Hz1/2/W；在0.332 THz的响应率可达7.74 A/W，NEP低于1.75×10-12 W/Hz1/2，D*高于6.7 ×108 cm·Hz1/2/W；同时器件在太赫兹波段具有小的时间常数(7~8 μs).该项工作突破了传统光子探测的带间跃迁，实现了可室温工作、高响应率、高速响应以及高灵敏度的太赫兹探测器件.
太赫兹探测器 二维材料 terahertz detector two-dimensional material Bi2Te3 Bi2Te3 红外与毫米波学报
2019, 38(4): 04459
Author Affiliations
Abstract
1 School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
2 State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
3 University of Chinese Academy of Sciences, Beijing 100049, China
4 Key Laboratory of Space Active Opto-electronics Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
5 e-mail: zmhuang@mail.sitp.ac.cn
6 e-mail: EDHZHANG@ntu.edu.sg
Millimeter and terahertz wave photodetectors have a wide range of applications. However, the state-of-the-art techniques lag far behind the urgent demand due to the structure and performance limitations. Here, we report sensitive and direct millimeter and terahertz wave photodetection in compact InGaAs-based subwavelength ohmic metal–semiconductor–metal structures. The photoresponse originates from unidirectional transportation of nonequilibrium electrons induced by surface plasmon polaritons under irradiation. The detected quantum energies of electromagnetic waves are far below the bandgap of InGaAs, offering, to the best of our knowledge, a novel direct photoelectric conversion pathway for InGaAs beyond its bandgap limit. The achieved room temperature rise time and noise equivalent power of the detector are 45 μs and 20 pW·Hz 1/2, respectively, at the 0.0375 THz (8 mm) wave. The detected wavelength is tunable by mounting different coupling antennas. Room temperature terahertz imaging of macroscopic samples at around 0.166 THz is also demonstrated. This work opens an avenue for sensitive and large-area uncooled millimeter and terahertz focal planar arrays.
Photonics Research
2019, 7(1): 01000089
1 中国科学院 长春光学精密机械与物理研究所, 吉林 长春 130033
2 中国科学院大学, 北京 100049
随着高铁的普及, 列车螺钉松动、车身变形等安全问题渐渐引起了人们的重视, 如何检测高铁车身是本文要研究的问题。本文采用激光三角法测量模型, 当线结构光扫描高铁车身时, 可以根据激光条纹的畸变程度, 判断高铁列车是否存在安全隐患, 而如何快速、精确地提取激光条纹中心线是首先要解决的问题。在考虑了光源选择、环境噪声、被测物反射等因素的基础上, 首先对图像进行预处理, 选择中值滤波去除噪声, 然后用最大类间方差法将目标区域与背景区域分割; 最后, 用改进的灰度重心法对目标区域进行中心线提取。本文在FPGA上实现了对分辨率为1 024 pixel×200 pixel图像的处理, 实验结果表明, 提取光带中心线用时不超过0.97 ms, 能够满足高铁检测系统对光带中心线提取实时性和准确性的要求。
中值滤波 最大类间方差法 灰度重心法 median filter OTSU gray barycenter method FPGA FPGA
