近红外光谱仪InGaAs前端电路系统研究

Study on InGaAs-Based Front End Cricuit System for NIR Spectrometer

针对基于MEMS微镜的长波近红外光谱仪的具体参数要求,分析了InGaAs探测器的前端光电转换放大系统的设计原理和方法,设计并实现了该系统。系统主要由前置放大电路、Sallen-Key电路以及温控电路组成。仿真与实验结果表明:系统将光信号成功放大,且增益与带宽满足光谱仪要求,其中温控精度±0. 1℃,降低了暗电流的影响,提高了探测效率。研究工作涉及的原理与方法,对InGaAs探测器高灵敏、低噪声、低成本的光电转换与放大的实现具有指导与借鉴作用。

To meet the requirements of long wave near-infrared(NIR)spectrometer based on MEMS micromirror,theoretical principles and methods of designing InGaAs photoelectric conversion and amplification circuit system at front end were introduced.The circuit system was designed and implemented,which is mainly composed of a preamplifier circuit,a Sallen-Key filter circuit and a temperature control circuit.Both simulation and experimental results show that the circuit system successfully amplifies the optical signal with gain and bandwidth fitting the spectrometer requirements.The temperature control circuit achieved temperature accuracy of±0.1℃,which reduced the influence of dark current and improved the efficiency of the detector.The principle and method are of guidance to the implementation of InGaAs photoelectric conversion and amplification circuit system with high sensitivity,low noise,and low cost.