高增益双层组合GaAs光电导开关设计与实验研究

设计制备了一种由双层半绝缘GaAs:EL2晶体组成的新型超快光电导功率开关.由于触发状态下双层GaAs晶体之间满足动态分压关系，使该开关在强电场偏置下触发时，双层GaAs晶体既能先后发生高增益过程，又能相互抑制对方进入锁定状态，开关输出为近似方波的双峰脉冲.因此，这种开关的工作方式既具有非线性模式特有的所需触发光能小、上升速度快等优点，又具有线性模式特有的重复工作频率高、使用寿命长等优点.偏压6500V时用脉宽8ns、能量3mJ的1064nm激光触发，输出电脉冲的上升沿为13.2ns，下降沿为54.6ns关键词：光电半导体开关高增益锁定效应

Design and performanec of a high-gain double-layer GaAs photoconductive switch

A new kind of ultra-fast power photoconductive semiconductor switch with double-layer semi-insulating GaAs:EL2 is designed and prepared. Because the distribution of voltage between the triggered double GaAs layers is dynamic, when biased at a high electric field, the double layers go into the high-gain state one after the other but prevent each other from entering the Lock-on state, so the output electric pulse has double peaks and looks like a rectangular wave. This working mode not only has the strong points of the nonlinear mode, such as the required laser energy is far less and the rise time is shorter than that of the linear mode, but also has the merits of the linear mode, such as the repetition frequency is higher and the life is far longer than that of the nonlinear mode. Biased at 6500 V and triggered by an 8 ns, 3 mJ and 1064 nm laser pulse, the rise time of the output electric pulse is 13.2 ns, the fall time is 54.6 ns, the full width at half maximum is 148.4 ns, the first peak is 885 V and the second peak is 897 V. With the bias voltage increasing, the rise time nearly keeps a constant, the width and fall time decrease slightly and the double peaks increase obviously.