倾斜入射时薄膜窄带滤光片的s和p偏振光的带宽会随着入射角度的增大出现分离,限制了滤光片的调谐范围。分析了偏振光带宽分离现象出现的原因和其与滤光片镜层膜系结构的关系,并得到了消除偏振光带宽分离现象的方法。根据该方法对前期设计的100 GHz密集波分复用(DWDM)系统四腔角度调谐窄带滤光片进行了改进,结果表明,该方法能有效的解决偏振光带宽的分离问题,扩大调谐范围。

The bandwidth of s-polarization and p-polarization will separate when the narrow-band thin-film filter is in tilted incidence,which will limit the tunable range of the filter. The phenomenon of the polarization bandwidth separation and its relation to the mirror layers of the filter are analyzed. A method about eliminating the polarization bandwidth separation is also presented. According to this method,a former designed 100 GHz dense wavelength division multiplexing four-cavities angle-tuned narrow-band filter is improved. The simulation results prove it can eliminate the polarization bandwidth separation and enlarge the tunable range.