Optical cut-off filter

In an optical cut-off filter in the form of a multilayer system comprising a sequence of dielectric layers A and B interposed between a transparent bordering medium having an index of refraction n.sub.0, and with an index of refraction n.sub.A for each of the layers A and an index of refraction n.sub.B for each of said layers B selected so that, for a preselected radiation angle of incidence .theta., the pass band of the filter has an envelope E.sub.s of the reflecting secondary maxima for the s-component vibrating perpendicular to the radiation plane of incidence and an envelope E.sub.p for the p-component vibrating parallel to the radiation plane of incidence of the electrical field vector of the incident radiation, and wherein each envelope has a zero location, the improvement comprising having the indices of refraction n.sub.A and n.sub.B of the dielectric layers A and B of the filter selected so that the zero locations of the two envelopes E.sub.s and E.sub.p lie at somewhat different wavelengths.