用于MHz重频光导开关触发的光纤分光系统设计

摘要

A fiber system was constructed to trigger photoconductive semiconductor switch(PCSS) at MHz operation frequency.The fibers in fiber system are arranged in alveolate position and each group has different lengths to make stable time delay.This paper focuses on the calculation of fiber system,group division and program design.Calculation program approves:With the increases of ratio of division radius to beam radius,the efficiency of fiber splitter increases until it reaches a certain point.With stable beam diameter the efficiency of fiber splitter decreases with the increasing of number of plies of fiber;With the stable of radical of fiber system,the maximum variance in the energy contained in each pulse of laser decreases versus the increasing of number of plies of fiber.Experiment has proved that the 10 MHz fiber splitter in output 4 laser pulse bursts and the maximum variance in the energy contained in each pulse is 6.80％ while the efficiency of system is 38.07％.%为了实现光导开关以MHz重复频率运行,设计了通过延迟产生MHz序列重复频率触发光的分光系统.分光系统由多根类蜂窝状排布的光纤组成并分为数组,各组光纤长度不同以产生时间序列.进行了光纤分光系统的理论计算,设计了分组程序,获得了各根光纤的输出端能量占比,实现了光纤输出端的分组设计优化.计算结果表明:当分光系统半径与激光器焦斑之比增大时,分光系统效率增高,达到一定数值后,分光系统效率趋于稳定;当激光器焦斑大小不变时,光纤层数增大,分光系统效率变小;当触发光脉冲数不变时,在一定范围内,光纤层数增大,输出端激光能量的最大相对误差变小.实验结果表明:四脉冲10 MHz分光系统实现了周期为100 ns的4个光脉冲输出,输出端能量最大相对误差6.80％,系统效率为38.07％.