中文摘要：

为了探索高性能透射式GaAs光电阴极的特征结构,对光电阴极量子效率公式进行了光谱反射率与短波截止限的修正,并利用修正后的公式对ITT透射式GaAs光电阴极量子效率（≈43%）曲线进行了拟合,得到拟合相对误差小于5%时的结构参数为：窗口层Ga1-xAlxAs的厚度介于0.3—0.5μm,Al组分x值为0.7,发射层GaAs的厚度介于1.1—1.4μm.另外,根据拟合结果讨论了均匀掺杂透射式GaAs光电阴极的优化结构参数,如果光电阴极具有0.4μm厚的Ga1-xAlxAs（x=0.7）窗口层和1.1—1.5μm厚的GaAs发射层,则积分灵敏度可以达到2350μA/lm以上.

英文摘要：

To explore the structural feature of high performance transmission-mode GaAs photocathode,the optical properties and shortwave limitation for the transmission-mode quantum efficient formula is modified.By using the modified formula,a high quantum efficient（≈43%） curve of ITT is well fitted.A series of structural parameters is obtained with in a relative error less than 5%,which indicates that the thickness of the Ga1-xAlxAs window layer is 0.3—0.5 μm,the Al mole value is 0.7,and the thickness of the GaAs active layer is 1.1—1.4 μm.In addition,an optimized structure for the uniform-doping transmission-mode GaAs photocathode is suggested based on the fitted results.When the thickness of the Ga1-xAlxAs（x=0.7） layer and the GaAs layer are 0.4 μm and 1.1—1.5 μm respectively,the integral sensitivity can exceed 2350 μA/lm.