Stabilization of the spectral characteristics of reflective interference filters within a given range of angles of incidence

Abstract

This research considers the influence of the structure of an interference reflective filter, structure of which includes interference layers made of non-absorbing dielectric materials, on the stability of its spectral characteristics with a change in the angle of incidence. A reflective filter is formed from the layers of equal or multiple optical thickness made of two film-forming materials. Our research has shown that with reducing difference between refractive indices of the filmforming materials, the bandwidth of stop-band decreases. The FWHM of stop-band of the filter is determined by the refractive indices of the film-forming materials. The dependence of stop-band shift on the wavelength scale with a change in the angle of incidence on the multilayers of dielectric structure has been established. The obtained function allows to impose restrictions on the film-forming materials to ensure a minimum shift of the spectral characteristic in a wide range of the angle of incidence.