Reflectance diagram-aided technique for optical coating design and monitoring

Reflection filter with high reflectivity and narrow bandwidth

A kind of reflection filter with a narrow bandwidth and high reflectivity is designed as being composed of an all-dielectric Fabry-Perot filter, a high-reflectivity Ag film, and especially an ultrathin metallic film, n approximately = k. Exemplary structures and some formulas concerning spectral-reflection performances, such as general reflectivity, maximum reflectivity, and the halfwidth of the reflection band, are given. Experiments show the validity of this design.