中文摘要：

利用流体模型对光生载流子的输运进行了模拟研究,结果表明载流子在输运过程中形成的光激发电荷畴是产生电脉冲超快上升特性的主要原因.对光激发电荷畴的形成和吸收过程的进一步研究表明：1）形成过程中的光激发电荷畴增强了电子的浓度梯度;2）光激发电荷畴在被阳极吸收的过程中,光电导开关偏置电压的快速下降能促进电流上升速度.光激发电荷畴的形成和吸收两大过程共同作用下,形成了电脉冲的超快上升特性.

英文摘要：

In the lock-on model of semi-insulating GaAs photoconductive switches,the output current pulse has ultra-fast rise character,the rise time can be even less than that of the laser pulse.Fluid model is used to simulate the transport of photo-induced carrier.The results show that photo-activated charge domain formed in the transport process of carriers is the main cause of ultra-fast rise time.Further studies on the establishment of photo-activated charge domain and the absorption process show：1.The photo-activated charge domains during the establishment enhance the electron density gradient.2.When the photo-activated charge domains are absorbed by the anode,rapid decline of bias electric voltage will accelerate the rise rate of output current pulse.Due to the two processes,the output current pulse in the lock-on model shows ultra-fast rise character.