Patent attributes
An optical element has layers formed on a substrate, including alternating first and second layers having first and second refractive indices, nL and nH that exhibit a spectral characteristic, providing, for incident light at a predetermined wavelength and directed toward the optical element within a range of angles bounded by first and second incident angles θ1 and θ2, between 0 and 80 degrees and differing by at least 1 degree, substantially linear polarization-averaged attenuation of the incident light energy wherein, for any incident angle θn between θ1 and θ2, Aθn is the corresponding polarization-averaged attenuation, and wherein the polarization-averaged attenuation at Aθn at angle θ1 is less than or equal to an optical density value of 0.2 and the polarization-averaged attenuation Aθn at angle θ2 exceeds an optical density value of 4.
