Firstly,We analyze the character of Nd:YAG,BBO and LBO,For Nd:YAG crystal and select the Nd:YAG as the gain medium and LBO as doubling-frequency crystal.

• 首先，我们对增益介质的性质和非线性晶体BBO和LBO的一些性质进行了比较，选取Nd：YAG作为增益介质，LBO作为倍频晶体。