Study on High Sensitivity and Low Noise Electro-Optic Terahertz Detector
CHEN Long-chao1,2, FAN Wen-hui1
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
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).
陈龙超, 范文慧. 高灵敏度低噪声太赫兹电光探测器研究[J]. 电子学报, 2012, 40(9): 1705-1709.
CHEN Long-chao, FAN Wen-hui. Study on High Sensitivity and Low Noise Electro-Optic Terahertz Detector. Chinese Journal of Electronics, 2012, 40(9): 1705-1709.
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2012, Vol. 40 
