高功率激光系统中全息“热像”效应

 对高功率激光系统中存在的一种类似于小尺度自聚焦的非线性过程“热像”效应进行了理论分析和模拟计算。当一束经过遮光物调制的激光光束通过非线性介质后，在随后的光路上将产生一个亮点，即“热像”。“热像”处的光强比背景光强大几倍，因此位于“热像”附近位置的光学元件很可能遭受损伤。从全息成像的角度对“热像”的形成过程进行了分析。结果表明：“热像”的位置处于以非线性介质为中心与遮光物大约对称的地方，“热像”的光强是原始光强的(1+B)2倍。计算机模拟与理论计算结果吻合较好，验证了上述结果。

Nonlinear hot holograpgic image in high power solid-state laser systems

A theoretical analysis and results of numerical calculations for the hot image formation in high power solid-state laser system are presented. According to holographic imaging theory, an approximately functional expression for the hot image intensity from opaque scatterer is derived, showing an intensity several times as much as the background light intensity. The hot image appears in a plane located downstream from the nonlinear medium at a distance equal to that from the scatterer to the medium. It is found that the hot image intensity and location are accurately predicted by theory and numerical calculations.