Patent ID: 6208466
Filing Date: 2001-03-27
Classification: G02B

Abstract:
A dielectric reflector comprising:a dielectric stack of optical repeating units including at least two different materials having different refractive indices, the stack having a critical angle at which light propagating in the stack will undergo total internal reflection at an interface of the stack with air;a first surface optically coupled to the dielectric stack and selectively treated to couple at least a portion of light incident on the first surface into the dielectric stack at a propagation angle above the critical angle; anda second surface optically coupled to the dielectric stack and selectively treated to couple at least a portion of light propagating in the dielectric stack at an angle above the critical angle out of the stack, wherein a coupling efficiency of at least one of the first and second surfaces, for coupling light into or out of the stack with a propagation angle above the critical angle, is different at different regions of the dielectric stack.