基于p偏振光双面反射的薄膜传感器光学参数的优化

ｐ偏振光在镀膜平板玻璃上、下表面反射光强比γ的角度调制曲线的性状与膜层光学参数密切相关。分析了γ与膜层折射率、消光系数及膜厚的相对梯度随光参数变化的着急为基于ｐ偏振光双面反射的薄膜传感器选择最佳参数提供了理论依据，计算表明该类型传感器对膜层折射率的测量分辨率高达１０＾－７。对不同工艺条件下得到的溶胶－凝胶ＳｎＯ２膜进行光学参数测定及初步气敏实验，结果表明ｐ偏振光双面反射可作为高灵敏度光化学传感器的

Optimization of Optical Parameters of the Film Sensor Based on p-Polarized Reflectance

The characteristic of the angular modulation curves of the reflectance ratio γ for p-polarized beams from both sides of coated plane glass is closely related to the optical parameters of the films. The dependence of relative gradients of γ to the refractive index n, extinction coefficient k and thickness h of the films on the optical parameters are obtained theoretically, which provides theoretical basis for the optimization of parameters. By data simulation, the resolution of refractive index of film sensor based on the calculation is predicted to be less than 10-7. It has been measured that the optical parameters of sol-gel SnO2 films under different technological conditions and the sensitivity to the testing gas. The results indicate that the method of the p-polarized reflectance can be widely used in high sensitivity optical chemical sensors.