脉冲辐射探测信号模拟光纤传输系统

Analog optical fiber transmission system appliedin pulsed radiation detection

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-3 dB带宽为DC^155 MHz,线性动态范围> 40 dB(100倍),输出噪声峰-峰值<3 mV。该系统适用于对传输带宽、安全性等要求高的科学研究中。

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 by 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 with dark current correction.The experimental measurement results of the system indicate that its bandwidth is DC^155 MHz,linear dynamic range is 40 dB,output peak-to-peak noise is less than 3 mV.The results show that the system is suitable for scientific research with high requirements on transmission bandwidth and security.