针对纳秒量级调Q 宽频带光纤激光器，分别模拟了利用光栅角色散补偿(ASD)，棱镜ASD 以及晶体级联方法对倍频效率的影响。采用LBO 晶体Ⅰ类相位匹配，通过数值求解高斯光束三波耦合方程，得到了入射基频光线宽、聚焦光斑位置、聚焦光斑大小以及晶体长度对倍频转换效率的影响，并对晶体参数进行优化。计算结果显示：直接倍频时，对于5 nm 宽频带激光，倍频效率只有17%；采用光栅角色散补偿可以在大光谱范围内倍频效率达到70%以上；棱镜提供的补偿较小，但也能使倍频效率提高50%；三块晶体级联可以使倍频效率提高130%。

The effect of the role on the second harmonic generation of the Q-switched broadband optical fiber laser are simulated by using the methods of grating angular spectral dispersion (ASD), prism ASD, and crystal cascade scheme. LBO crystal type I phase is used to match, by numerically solving the three wave coupling equations of Gauss beam, the incident light frequency width, focal position, focal spot size and crystal thickness influence on the conversion efficiency are obtained, and the parameters of crystal is optimized. The calculation results show that the second harmonic generation (SHG) efficiency is only 17% with the laser bandwidth of 5 nm; the use of the grating ASD can achieve frequency doubling efficiency of more than 70% in a large spectral range; the compensation of the prism is smaller, while can improve the efficiency by 50%; three crystal cascade can make the efficiency increased by 130%.