Patent ID: 7570428
Filing Date: 2009-08-04
Classification: G02B

Abstract:
1. A multilayer minus filter for reflecting a light having at least one reflection wavelength λ 0 and transmitting a light having a wavelength other than the reflection wavelength λ 0 , the filter comprising: a transparent substrate; and a repetition layer formed on a surface of the substrate including a plurality of high refractive index layers having an average optical thickness H per layer and a plurality of low refractive index layers having an average optical thickness L per layer, the repetition layer having an alternative stack of high and low refractive index layers, and satisfying the following formulas: wherein the repetition layer is formed by an ion assisted process technology, and wherein a reflection band utilized with respect to a light incident obliquely on the surface of the filter, the reflection band appearing in reflection wavelength λ