波分复用薄膜带通滤光片的中心波长温度稳定性

讨论了影响波分复用薄膜滤光片中心波长漂移的因素 ,着重分析了滤光片的温度稳定性。根据实验结果 ,借助于高桥模型 ,分析计算了滤光片的折射率温度系数、线膨胀系数和泊松比以及它们对温度漂移的影响。得到了Ta2 O5/SiO2 滤光片薄膜的折射率温度系数、线膨胀系数、泊松比分别为 1× 10 -5℃-1,5× 10 -7℃-1和 0 12 ,指出了这三个参量是影响温度稳定性最重要的因素 ,特别是薄膜的折射率温度系数。对特定的基板热膨胀系数 ,通过调节滤光片的干涉级次和间隔层材料 ,可望得到零温度漂移的稳定滤光片。

Temperature Stability of the Central Wavelength for WDM Thin Film Bandpass Filters

The factors influenced central wavelength shift of wavelength division multiplexing (WDM) narrow-band filters are discussed. The temperature stability for such filters is emphasized. Based on Takashashi model,the effect of the temperature coefficient of refractive index,coefficient of linear expansion and Poisson ratio on temperature stability of the central wavelength of the filters is analyzed and calculated by using authors′ software. The temperature coefficient of refractive index,linear expansion coefficient and Poisson ratio of the Ta2O5/SiO2 narrow-band filters are 1×10-7 ℃-1 and 0.12 respectively. These three parameters are most important factors for the temperature stability of the filters, especially for the temperature coefficient of refractive index. For given substrate with certain linear expansion coefficient, the filter with a nearly zero wavelength shift is expected by means of adjusting interference order, cavity number and spacer material of the filters.