中国激光, 2019, 46 (12): 1203002, 网络出版: 2019-12-02
278 nm全固态激光系统倍频分离膜的研制 下载: 1189次
Development of Separation Film for Frequency Doubling in 278 nm All-Solid-State Laser System
薄膜 倍频分离膜 热效应 场效应 激光损伤阈值 films separation film for frequency doubling thermal-effect field-effect laser induced damage threshold
摘要
根据278 nm激光系统的技术要求,研制了一种倍频分离膜,用于二倍频激光和四倍频激光的分离。实验以牌号为JGS1的石英玻璃作为基底,结合激光损伤热效应机理及材料的本征吸收,选择金属铪和UV-SiO2作为薄膜材料。利用Macleod膜系设计软件分析电场强度分布随膜系周期的变化规律,依据薄膜设计理论和激光损伤场效应机理,完成了倍频分离膜的设计。采用X射线光电子能谱仪、分光光度计和ZYGO干涉仪表征了薄膜的化学成分、光学性能和表面粗糙度。对实验结果进行对比分析,优化薄膜的生长工艺,减小了外因吸收。测试结果表明,当入射角为45°时,278 nm波长处的透过率为98.82%,556 nm波长处的反射率为99.80%,在40°~50°宽入射角范围内,光谱性能均可达到技术指标,激光损伤阈值为12.53 J/cm 2,满足使用要求。
Abstract
To meet the technical requirements of the 278-nm laser system, a separation film for frequency doubling is developed to separate the double frequency laser and quadruple frequency laser. Combined with the laser damage thermal effect and intrinsic absorption of the materials, Hafnium and UV-SiO2 are chosen as film materials and the well-cleaned JGS1 quartz glass is used as the substrate. According to the thin film theory and laser damage field effect mechanism, the periodicity variation in electric field intensity distribution of the film is studied and design of the frequency separation film is completed by Macleod software. The chemical composition, optical properties, and surface roughness of the film are analyzed using X-ray photoelectron spectroscopy, spectrophotometer, and ZYGO interferometer, respectively. In comparison with experimental results, the deposition technology of the film is optimized to improve the film growth process and reduce external absorption. Experimental results show that the transmittance of films is 98.82% at 278 nm and reflectance is 99.80% at 556 nm when the incident angle is 45°. In the wide incident angle range of 40°-50°, spectral performance can meet the requirements of the target. The laser-induced damage threshold is 12.53 J/cm 2, which meets the needs of use.
付秀华, 陈成, 胡章贵, 熊仕富, 张静, 王菲, 王晨鑫. 278 nm全固态激光系统倍频分离膜的研制[J]. 中国激光, 2019, 46(12): 1203002. Xiuhua Fu, Cheng Chen, Zhanggui Hu, Shifu Xiong, Jing Zhang, Fei Wang, Chenxin Wang. Development of Separation Film for Frequency Doubling in 278 nm All-Solid-State Laser System[J]. Chinese Journal of Lasers, 2019, 46(12): 1203002.