高速平衡零拍探测器的设计与实现.pdfVIP

高速平衡零拍探测器的设计与实现 摘要：平衡零拍探测器存在共模抑制比小、响应带宽低等问题。针对以上问题，尝试从两方 面进行改进：一方面，通过测试探测器中光电检测器（PIN 光电二极管）的响应特性，选择性 能相近的器件进行平衡探测，以提升共模抑制比；另一方面，采用跨阻放大与比例运放级联 的方式对光电流信号进行提取，解决一级采样放大器增益带宽积局限的问题，在保障灵敏度 的同时提升探测器的响应带宽。由此实现了300 MHz 的平衡零拍探测，共模抑制比高达 66 dB ，并有效检测了光信号中的量子散粒噪声，为高速灵敏探测提供了一种有效技术方案。 关键词：平衡零拍探测；跨阻放大器；量子噪声；共模抑制比；散粒噪声与电子噪声比值 Design and implementation of high-speed balanced homodyne detector Abstract: Balanced homodyne detectors have the disadvantages such as small common mode rejection ratio (CMRR) and low response bandwidth, etc. To address the problems, we designed a scheme to test the response characteristics of the photodetector (PIN photodiode) in the detector and selected devices with similar performance for balanced detection to improve the CMRR. Furthermore, the scheme of cascading transimpedance amplification and proportional operational amplifier were proposed to extract the photocurrent signal, which solved the problem of the limitation of the gain bandwidth product of the primary sampling amplifier and improved the response bandwidth of the detector while ensuring the sensitivity. As a result, we achieved 300- MHz balanced homodyne detection and the CMRR went up to 66 dB. We also detected the quantum shot noise in the optical signal. These achievements provide an effective technical scheme for high-speed sensitive detection. Keywords: balanced homodyne detection ； trans-impedance amplifier ； quantum noise ； common-mode rejection ratio ；shot noise to electronic noise 信号转化为光电压，另外还增加了二级比例运放   引　言 的设计，通过采用两级放大级联的方案，解决一 级采样放大器增益带宽积局限的问题，缓和平衡 平衡零拍探测器 （balanced homodyne 探测器增益与带宽之间相互制约的矛盾，最终实 detectors ，BHD ）在量子随机数产生、量子噪声 现了高共模抑制比的突破，在保障探测灵敏度的 分析、外差