对比研究了基频、二倍频和三倍频激光单独和同时辐照下熔石英光学元件的初始损伤和损伤增长规律，重点研究了基频和二倍频的加入对三倍频诱导初始损伤和损伤增长的影响，分析了基频和二倍频相对于三倍频的折算因子。研究结果表明：当基频和二倍频能量密度较低时，它们对三倍频损伤几率曲线的影响可以忽略，但会引起损伤程度的增加；在多波长同时辐照的损伤增长中，损伤增长阈值主要取决于三倍频的能量密度，而损伤增长系数与总的能量密度有关；折算因子可以同时反映初始损伤和损伤增长的波长效应和波长间的能量耦合效应。

The initial damage and damage growth of fused quartz optical elements irradiated by fundamental frequency, double frequency and triple frequency lasers alone and at the same time are studied comparatively. The effects of fundamental and double frequencies on the initial damage and damage growth induced by triple frequencies are emphatically studied. The conversion factors of fundamental frequency and double frequency relative to triple frequency are analyzed. Research results show that, when the energy density of fundamental frequency and double frequency is low, their influence on damage probability curve of triple frequency can be neglected. However, it will cause an increase in the degree of damage. In multi-wavelength simultaneous irradiation damage growth, the damage growth threshold mainly depends on the energy density of triple frequency, and the damage growth coefficient is related to the total energy density. The conversion factor can reflect both the wavelength effect of initial damage and damage growth and the energy coupling effect between wavelengths.