Abstract

As the thin-film filter is used in oblique incidence, the central wavelengths of the p-polarization and s-polarization will separate obviously, which will cause serious polarization dependent loss. With the analysis of phase relationship, the value of moderate refractive index can be obtained to coincide the central wavelengths of both polarizations. Based on the equivalent layers theory, the moderate refractive index can be replaced by a symmetral layers. The simulation and experimental results indicate that the stack can keep the central wavelengths of both polarizations coinciding in 20° oblique incidence.

© 2014 Optical Society of America