双级升压高速电光调Q驱动电路设计

Design of a High Speed Electro-Optic Q-Switch Driver Circuit by Double Stage Boost

电光调Q是获取高峰值功率激光脉冲的有效手段,传统单一脉冲变压器升压存在电光调Q电压调整范围受限、高压脉冲上升时间过长等问题。文章通过双级升压方式进行了高速电光调Q驱动电路设计,实现了电光调Q电压高幅值和高速率的需求。其中一级升压采用反激式变换器原理,输出幅值可调的一级高压,扩展了电压调整范围;二级升压采用马克思(Marx)发生器原理,通过电压倍增的方式输出二级高速高压脉冲信号。该设计电路与激光发射机驱动源的联试结果显示:通过调整反馈偏置直流工作点,使一级反激式变换器升压输出范围在150~550 V,二级Marx发生器升压输出范围1 500~4 000 V,高压脉冲上升时间小于30 ns;相比于传统单一变压器控制方法,调Q电压输出的范围更宽,增幅近1 000 V;高压脉冲上升时间更短,仅为23~28 ns。试验证明双级升压设计能够为电光调Q晶体提供调整范围更宽的高速率驱动高压,进而获得高峰值功率的激光脉冲。

Electro-optic Q-switch is an effective means to obtain laser pulseswith high peak power.The traditional single-pulse transformer has shortcomings such as limited voltage adjustment range and long rise time of high-voltage pulse.In this paper,the requirement of high amplitude and high speed for the electro-optic Q-switch voltage is realized by means of double-stage boost.The first stage boost uses the principle of flyback converter,and the voltage output can be adjustable,thus effectively extending the voltage adjustment range.The second stage boost uses the principle of Marx generator,and the second stage high-voltage pulse signal is outputby voltage multiplication.The experimental results show that by adjusting the operating point of the feedback bias DC,the boost output rangesfor the double stages are respectively 150~550 V and 1500~4000 V,and the rise time of high-voltage pulse is less than 30 ns.Compared with the traditional single transformer control method,the range of Q-switch voltage output is wider,with an increase of nearly 1000 V.The rise time is shorter,with nearly 40 ns reduced.The double-stage boost design can provide a high speed drive voltage with a wider adjustment range for the electro-optic Q-switch crystal and then obtain laser pulses with high peak power.