摘要
The peculiar photoconduction in semi insulating GaAs photoconductive switch being triggered by 1064nm laser pulse is reported.The gap between two electrodes of the switch is 4mm.When it is triggered by laser pulse with energy of 0 8mJ and the pulse width of 5ns,and operated at biased electric field of 2 0 and 6 0kV/cm,both linear and nonlinear modes of the switch are observed respectively.Whereas the biased electric field adds to 9 5kV/cm,and the triggered laser is in range of 0 5～1 0mJ,the peculiar performed characteristic is observed:the switch gives a linear waveform firstly,and then after a delay time of about 20～250ns,it outputs a nonlinear waveform again.The physical mechanism of this specific phenomenon is associated with the anti site defects of semi insulating GaAs and two step single photon absorption.The delay time between linear waveform and nonlinear waveform is calculated,and the result matches the experiments.
报道了用1064nm激光脉冲触发半绝缘GaAs光电导开关的一种奇特光电导现象．GaAs光电导开关的电极间隙为4mm，当偏置电场分别为2．0和6．0kV／cm时，用脉冲能量为0．8mJ，宽度为5ns的激光触发开关，观察到开关输出的线性和非线性工作模式．当偏置电场增至9．5kV／cm，触发光脉冲能量在0．5～1．0mJ范围时，观察到奇特的光电导现象，开关先输出一个线性电脉冲，经过大约20～250ns时间延迟后，触发光脉冲消失，开关又输出一个非线性电脉冲．这一奇特光电导现象的物理机制与半绝缘GaAs中的反位缺陷和吸收机制有关．分析计算了线性与非线性电脉冲之间的延迟时间，结果与实验观察基本吻合．
基金
国家自然科学基金资助项目(批准号:10390160
10376025
50477011)~~
