固体介质间隔层激光标准具性能的影响因素研究

针对固体介质间隔层的镀膜标准具, 以1 064 nm激光镀膜标准具为例, 首先研究了反射膜堆数对反射带宽、基底厚度以及对自由光谱区的影响:标准具的带宽随着膜层堆数增加而减小, 自由光谱区随着基板厚度的增加而减小;其次研究了基底误差对标准具中心波长定位和透过率的影响, 通过定量数值计算证明了基底误差可通过标准具的使用角度补偿;针对典型的H(LH)^m/Substrate/(HL)^mH和L(LH)^m/Substrate/(HL)^mL两个膜系结构, 研究了入射激光发散角对标准具中心波长偏移、通带半宽度、中心波长透过率和最大透过率的影响。随着激光发散角的增加, 中心波长向短波方向移动, 通带半宽度、中心波长透过率和最大透过率呈现下降的趋势, 并且第二个膜系结构的标准具性能优于第一个膜系结构的标准具。

Study on the influence factors of the characteristic of laser etalon with solid dielectric spacer-layer

For the laser etalon with solid dielectric spacer-layer, the effects of the stack numbers of reflection films on the reflection bandwidth, the thickness of substrate and the free spectral range are first studied by taking an example of laser etalon working at 1 064 nm. The results indicate that the bandwidth of the etalon decreases with the stack number increasing, and the free spectral range decreases with the thickness of substrate increasing. Then the effects of the deviation of substrate on the central wavelength and the transmittance of etalon are studied. The deviation of substrate thickness could be compensated by adjusting the working angle of the etalon through the numerical calculation. Further more, for the two typical coating structures such as H(LH)^m/Substrate/(HL)^m H and L(LH)^m/Substrate/(HL)^mL, the effects of the divergence angle of incident laser on the central wavelength, the half pass band width, the transmittance at central wavelength and the maximum transmittance are investigated. The results demonstrate that with the increasing of divergence angle, the central wavelength shifts to the shorter wavelength, and the half pass band width, the transmittance at central wavelength and the maximum transmittance show a downward tend. The performance of etalon with the coating structure of L(LH)^m/substrate/(HL)^mL is superior to that of H(LH)^m/substrate/(HL)^mH.