脉冲辐射探测信号模拟光纤传输系统

为实现极端实验环境下脉冲辐射探测信号的远距离 传输,采用电光转换和光电转换的方法设计了 一套模拟光纤传输系统。该系统基于DFB激光器的强度直接调制特性实现了电光转换；以运 算放大器为主 体构建了激光器驱动电路；利用专用集成芯片MAX1968实现了激光器 半导体PN结的无死区温度控制。为 提高系统测试精度,光接收端采用带有暗电流校正的平衡PIN 前置放大器将光信号还原为电 信号,以提高 系统动态范围。最后,实验测试了系统性能指标。结果表明,系统的－3dB带宽为DC~155 MHz,线性动态 范围> 40 dB(100倍),输出噪声峰-峰值<3mV。该系 统适用于对传输带宽、安全性等要求高的科学研究中。

Analog optical fiber transmission system appliedin pulsed radiation detection

An analog optical fiber transmission system was developed for pulse signal transmission.The pulse electric signal was converted to optical signal by means of electro-optic conversion.After long distance transmission,the optical signal was recovered b y means of photo-electric conversion.The focus of the paper is on the modulation mode of the laser,the temperature control technique without dead zone and the balanced-PIN detector w ith dark current correction.The experimental measurement results of the system indicate that its bandwidth is DC~155MHz,linear dynamic range is 40dB,output peak-to-peak noise is less tha n 3mV.The results show that the system is suitable for scientific research with high requi rements on transmission bandwidth and security.