用红外激光脉冲触发半绝缘GaAs光电导开关的实验研究

Experimental study of semiinsulating GaAs photoconductiveswitch triggered by infrared laser pulse

报道了用光子能量低于GaAs禁带宽度的红外激光脉冲,触发电极间隙为3mm和8mm的半绝缘GaAs光电导开关的实验结果。使用单脉冲能量为1.9mJ的1064nmNd:YAG激光触发开关,在偏置电压分别为3kV和5kV条件下,光电导开关分别工作于线性和非线性模式。用900nm半导体激光器和1530nm掺铒光纤激光器分别进行触发实验,得到了重复频率分别为5kHz和20MHz的电脉冲波形。结果表明,半绝缘GaAs光电导开关可以吸收大于本征吸收限波长红外激光脉冲。

The semiinsulating GaAs photoconductive switches, whose deep energy defect is introduced by particle beam irradiation, are described. The experiments of two kinds of switches with the distance of 3mm and 8mm between two electrodes respectively, triggered by infrared laser pulse are reported, and the photon energy of the trigger laser is lower than the GaAs bandgap. The output electronic pulse whose repetition rates are 5kHz and 20MHz are observed when triggered by 900nm diode laser and 1 530nm optical fiber laser respectively. The semiinsulating GaAs photoconductive switch can operate in linear mode and nonlinear mode respectively, when they are switched at 3kV and 5kV and triggered by 1 064nm Nd:YAG laser with the energy of 1.9mJ. The experiments indicated the semiinsulating GaAs photoconductive switch can absorb infrared laser obviously, and this nonintrinsic absorption mechanism is also discussed in the paper.