连续激光辐照下光学材料损伤阈值的光斑效应

Spot Size Effect of CW Laser Induced Damage Threshold in Optical Materials

实验发现 ,光学材料的激光损伤阈值对激光光斑大小有强烈的依赖关系。研究了连续激光和匀质材料相互作用的机制 ,针对小光斑情形的材料响应和大光斑情形的结构响应分别提出各自不同的物理模型来解释光斑效应。研究表明 ,材料响应中的光斑效应基于热传导引起的光斑区热弥散 ,而在结构响应中 ,边界条件不同 。

Experimental research shows that laser induced damage thresholds (LIDT) are strongly dependent on the beam radius. The thermo-elastic model describing the interaction of CW laser with uniform optical materials is established, and material response and structure response are studied independently. Study shows that spot size effect in material response results from the energy loss of the irradiated area. As for structure response, different mechanical boundaries result in different relationships of LIDT with radius of laser beam.