三硼酸锂晶体上1064 nm, 532 nm, 355 nm三倍频增透膜的设计

采用矢量法设计了三硼酸锂晶体上1064 nm、532 nm和355 nm三倍频增透膜,结果表明1064 nm、532 nm和355 nm波长的剩余反射率分别为0.0017％、0.0002％和0.0013％。根据误差分析,薄膜制备时沉积速率精度控制在＋5.5％时,1064 nm、532 nm和355 nm波长的剩余反射率分别增加至0.20％、0.84％和1.89％。当材料折射率的变化控制在＋3％时,1064 nm处的剩余反射率增大为0.20％,532 nm和355 nm处分别达0.88％和0.24％。与薄膜

1064 nm, 532 nm, 355 nm frequency-tripled antireflection (AR) coating was designed on LiB3O5 (LBO) substrate with vector method. The design result showed that the residual reflectivity at wavelength of 1064 nm, 532 nm and 355 nm could be 0.0017%, 0.0002% and 0.0013%, respectively. According to error analysis, the reflectivity increased to 0.20% at 1064 nm, 0.84% at 532 nm and 1.89% at 355 nm when the precision of deposition rate was controlled at ＋5.5%. If the refractive index accuracy was ＋3%, the reflectivity reached 0.20% at 1064 nm, 0.88% at 532 nm and 0.24% at 355 nm, respectively. The refractive index had more effect on the residual reflectivity of the antireflection coating than the physical thickness. From the incident medium to the substrate, the thickness variation of the second layer had the most effect on the reflectivity of the antireflection coating at 1064 nm and 355 nm, followed by the first layer, and the layer next to the substrate was most insensitive. At 532 nm, the first and third layers were the sensitive layers of the antireflection coating design. The reflectance of the antireflection coating at 1064 nm, 532 nm and 355 nm increased to 0.15%, 0.31% and 1.52%, respectively due to the dispersion of the coating materials.