Codeposition of Continuous Composition Rugate Filters

Abstract

Sinusoidal refractive index profile filters (rugates) are ideally monolithic structures, having no interfaces between dissimilar materials. This is expected to avoid the stress and delamination problems which often arise in thick multilayer thin film filters. The sinewave refractive index profile demonstrates a significant suppression of higher frequency reflective sidebands. Furthermore, multiple, independently selectable reflection bands can be obtained by a superposition of sinewaves of appropriate period. This is demonstrated in Fig.1.