高反镜表面颗粒物在连续激光辐照下的吸收特性

Absorption Characteristics of Particles on the Surface of A Highly Reflective Mirror under Continuous-Wave Laser Irradiation

摘要:

光学元件表面吸收损耗是衡量光学元件光学性能的重要指标,颗粒污染物附着通常会引起光学元件表面吸收损耗大幅增加。基于红外热像仪温升检测方法,研究了几种典型颗粒污染物对高反镜表面吸收损耗的影响,并根据颗粒污染物分布特点建立阶梯式分布吸收和离散分布吸收模型。考虑测温精度受红外热像仪空间分辨率的影响,提取单像素点内温升数据进行有限元分析,获取精度与单像素点相当的镀膜元件表面局部吸收损耗,结合显微镜下扫描结果进一步优化仿真模型,从而获得了薄膜元件表面颗粒污染物的吸收损耗。

Abstract:

The surface absorption loss of an optical component is an important index used to measure its optical performance. The attachment of pollutant particles usually causes a significant increase in the surface absorption loss of an optical component. This study used the temperature rise detection method of an infrared thermal imager to investigate the influence of several typical pollution particles on the surface absorption loss of a highly reflective mirror. Stepped and discrete distribution absorption models were established based on the distribution characteristics of these pollutant particles. Considering that the temperature measurement accuracy was affected by the spatial resolution of the infrared thermal imager, the temperature rise data for a single pixel were extracted for a finite element analysis, and the local absorption loss on the surface of the coated element with an accuracy equivalent to that of a single pixel was obtained. Microscopy scanning results were used to further optimize the simulation model and obtain the absorption loss of particulate pollutants on the surface of a thin film element.