窄带干涉滤光片抗击不同输出方式激光的损伤特性研究

利用Nd：YAG调Q单脉冲激光和自由脉冲激光对硬膜窄带干涉滤光片进行激光损伤阈值的测试，并且采用表面热透镜技术测量了滤光片的吸收率。实验发现：窄带干涉滤光片的吸收率和激光损伤阈值强烈依赖于辐照激光波长与窄带干涉滤光片通带的相对位置；在调Q单脉冲激光作用下，不同中心波长的滤光片损伤形貌存在明显的差别，而在自由脉冲激光作用下，各滤光片的损伤形貌则趋于相同．均表现为典型的热熔烧蚀破坏。根据实验结果，结合损伤形貌，通过驻波场理论对激光作用下滤光片内电场分布的分析与模拟．探讨了两种激光模式作用下滤光片的损伤特征和损

The laser-induced damage threshold(LIDT) and damage morphology of Ta₁O_5/SiO₁ narrow-band interference filters under single-pulse laser and free-running laser were investigated. The weak absorptance and the standing-wave fields of the filters have also been measured and analyzed. It was shown that narrow-band interference filters had unique laser-induced damage behaviors. All the filters exhibited a pass-band center dependent LIDT and absorptance behavior: LIDT of the samples decreased, as the sample’s pass-band center was closer to laser wavelength 1 064nm; Absorptances of the samples increased as the sample’s pass-band center was closer to laser wavelength 1 064 nm. Under single-pulse laser irradiation, the damage morphologies of the filters depended greatly on the irradiation wavelength’s relative position to the passband, while in the case of free-running laser, there was no difference among the damage morphologies of different peak wavelength. According to experimental results and theoretical analysis,the lase induced damage mechanism of the filters has been given.