倾斜非线性介质热像效应的实验研究

高功率激光系统中,热像的强度可以达到光学元件的损伤阀值,从而威胁系统的安全运行.以往对热像效应的研究主要针对光束正入射非线性介质的情况,而实际片状放大器中的介质片往往倾斜放置.实验研究了倾斜非线性介质的热像效应,结果表明,非线性介质倾斜引起热像的平移,且随介质倾斜角度的增加,热像位置平移的距离增加,其增加量与理论分析光束通过介质后的平移量符合较好,而热像的强度变化很小.所得结果对适当排布高功率激光系统中的元件以避免热像带来的损伤具有重要意义.

Experimental Study of Hot Image Effect through Tilted Nonlinear Medium Slab

In high-power laser system,hot image can be intense enough to damage expensive optical components,and hinder the safe operation of the laser system.Previous study of hot image effect has been concentrated on the case of the light beam normally incident on the nonlinear medium slab.However,the nonlinear medium slab in the realistic disk amplifier is tilted with respect to the propagation axis.An experimental study of hot image effect in an intense laser beam through a tilted nonlinear medium slab is presented.It is shown that,relative to the case of laser beam normally incident on the nonlinear medium slab,the location of the hot image will shift transversely,and the shift increment will increase with the incident angle increasing,while the intensity of the hot image is changed very little.These results are significant for appropriately laying out the optical components to avoid damage risks of hot image in high power laser system.