低抖动Q开关光电转换及触发系统设计

　　“Z-Pinch”装置对其激光触发气体闭合开关有严格时序要求。为实现四倍频 Nd : YAG激光器出光时刻的精确控制，开展了激光器Q开关光电转换及触发系统的研究。采用AVAGO公司的高速光电转换器件AVAGO2316TZ，将接收到的光信号转换成模拟电压信号，并以PECL(positive emitted-couple-logic)电平形式实现该电信号的板级传输与处理，最终，该信号作为IXYS公司的IXDD415的控制端，以实现低抖动，快前沿的电脉冲输出用以驱动Q开关。电路中采用了电感、电容、RC网络滤波方法，有效减小电源噪声对抖动的影响。该光电转换及触发系统在Z装置单路样机中得到应用，测试结果表明均方根抖动为70 ps，时延极差<1 ns。

　　Abstract:

　　“Z-Pinch” devices have strict timing requirements on the laser triggered gas closed switches. In order to trigger accurately control the Nd : YAG laser， a low jitter optic-electricity signal transfer and Q-switch trigger system was studied. Optic-electricity signal was transfered into analog voltage signal by AVAGO2316TZ，and the analog signal was transmitted and handled in the form of PECL. At last， the signal was connected with input pin of IXDD415. The output pulse of IXDD415 has characteristic of low jitter and fast rise phase. Inductance, capacitance and RC network filter were used in the circuit, which effectively reduced the jitter influence. This system is applied to Z device simplex prototype. The results testify that the RMS jitter is about 70ps，the range of jitter is less than 1ns.