光子学报, 2016, 45 (7): 070731001, 网络出版: 2016-08-18
用于355 nm紫外激光器的消偏振二向色镜
Depolarised Dichroic Mirror for the 355nm Ultraviolet Laser System
薄膜光学 紫外激光器 激光损伤 消偏振 光学性质 膜厚 Thin film optics Ultraviolet lasers Laser induced damage Depolarization Optical properties Film thickness
摘要
采用离子束辅助电子束成膜, 用双重膜厚监控方法监控各膜层厚度, 制备了45°入射、808 nm高反、1064 nm高透的消偏振二向色镜, 并用于全固态355nm激光器.将部分薄膜样品在250℃进行退火处理后, 用Lambda950分光光度计测试该样品的光谱性能;用表面热透镜技术测量退火前后该样品的弱吸收值; 用激光阈值损伤装置测试该样品在1064 nm调Q激光下的损伤阈值; 用NIKON显微镜观察样品在不同激光能量辐照下的破斑形貌.实验结果表明:波长为808 nm和1 064 nm时, 薄膜透射率分别为0.04%和99.6%, 符合设计要求, 满足全固态355nm紫外激光器系统所要求的光学性能指标; 退火后的弱吸收值较退火前有所降低; 在激光作用下薄膜产生微破坏喷出, 说明膜层不会向灾难性破坏演变.
Abstract
By using the ion beam assisted deposition to evaporate the materials and utilizing the double film thickness monitoring method to control the thickness of each layer, a depolarised dichroic mirror with the incidence angle of 45°, the spectrum 808nm reflected and 1064nm transmitted was prepared, which was used in an all solid state 355 nm laser. The partial thin film samples were annealed at 250℃, then the transmittance was measured with a Lambda 950 spectrophotometer; the weak absorption value of coatings was measured by a surface thermal lensing technique before and after annealing; the laser-induced damage threshold was tested by a 1 064 nm Q-switch pulsed laser; the morphology of the samples was observed by NIKON microscope under the different laser energy. The experimental results show that, the transmittances of the films are T1064 is 99.6%, T808 is 0.04%, which meet the design requirements, and the optical performance of the film can meet the requirements of the all solid state 355nm ultraviolet laser system; the weak absorption value is decreased after annealing; Micro destruction of the film is emitted under the action of laser, which proves that the film will not evolve to a catastrophic failure.
庄秋慧, 刘国军, 付秀华, 马孜, 王三强. 用于355 nm紫外激光器的消偏振二向色镜[J]. 光子学报, 2016, 45(7): 070731001. ZHUANG Qiu-hui, LIU Guo-jun, FU Xiu-hua, MA Zi, WANG San-qiang. Depolarised Dichroic Mirror for the 355nm Ultraviolet Laser System[J]. ACTA PHOTONICA SINICA, 2016, 45(7): 070731001.