电子学报 ›› 2012, Vol. 40 ›› Issue (9): 1705-1709.DOI: 10.3969/j.issn.0372-2112.2012.09.001

• 学术论文 •    下一篇

高灵敏度低噪声太赫兹电光探测器研究

陈龙超1,2, 范文慧1   

  1. 1. 中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室, 陕西西安710119;
    2. 中国科学院研究生院, 北京100049
  • 收稿日期:2011-12-06 修回日期:2012-02-24 出版日期:2012-09-25
    • 基金资助:
    • 国家高技术研究发展计划 (863计划)项目 (No.2011AAxxx2008A); 中国科学院百人计划基金项目 (No.J08-029); 中国科学院知识创新工程重要方向性项目 (No.YYYJ-1123-4); 国家重点基础研究发展计划 (973计划)项目 (No.2007CB310405)

Study on High Sensitivity and Low Noise Electro-Optic Terahertz Detector

CHEN Long-chao1,2, FAN Wen-hui1   

  1. 1. State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, Shaanxi 710119, China;
    2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2011-12-06 Revised:2012-02-24 Online:2012-09-25 Published:2012-09-25
    • Supported by:
    • Program of National High-tech R&D Program of China  (863 Program) (No.2011AAxxx2008A); 100 Talents Project of Chinese Academy of Sciences,  China (No.J08-029); Knowledge Innovation Projects of the Chinese Academy of Sciences (No.YYYJ-1123-4); National Program on Key Basic Research Project  (973 Program) (No.2007CB310405)

摘要: 本文选用相同光电响应灵敏度的高性能PIN光电二极管,将探测激光信号转换为电流信号,再通过低噪声电流-电压转换将电流信号转换为电压信号,通过采用具有很强共模信号抑制能力的差分放大器,不仅极大地抑制了太赫兹信号本身携带的噪声,也避免了探测激光强度扰动引起的测量误差.差分最后经过带通滤波器控制工作带宽和进行降噪处理,经由主放大器实现太赫兹信号输出.实验表明,该探测器具有高灵敏度、高信噪比、宽工作带宽等显著特点,完全满足了太赫兹时域光谱系统研究的需要.

关键词: 太赫兹波, 电光探测, 信噪比, 灵敏度, 太赫兹时域光谱

Abstract: An electro-optic terahertz (THz) detector with a newly-designed circuit was investigated.A pair of high-quality PIN photodiodes and a low-noise current-voltage conversion circuit were applied to convert the modulated probe laser to voltage signal.These two voltage signals were subsequently sent to a specially-designed differential amplifier with high common-mode-rejection-rate (CMRR) that largely restrain the noise of terahertz signal and avoid the disturbance of probe laser intensity.Then a band-pass filter was employed to control bandwidth and restrain noise of the detected signal.Finally,the weak THz signal was detected via a main amplifier.Experimental results show that the THz detector has high signal-to-noise-ratio (SNR),teeny distortion and wide bandwidth,which fully satisfy the requirement of terahertz time-domain spectroscopy (THz-TDS).

Key words: terahertz (THz), electro-optic detection, signal-to-noise-ratio (SNR), sensitivity, terahertz time-domain spectroscopy (THz-TDS)

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