Anti-reflective coatings on optical waveguides

Described herein is an anti-reflective waveguide, comprising: a planar waveguide substrate having a first index of refraction; a plurality of diffractive optical elements disposed upon a first surface of the waveguide; and an anti-reflective coating disposed upon a second surface of the waveguide, wherein the waveguide is planar and configured to propagate light by total internal reflection between the plurality of diffractive optical elements and the anti-reflective coating in a substantially first direction, and outcouple light in a second direction substantially orthogonal to the first direction, wherein the light propagating by total internal reflection comprises an s polarization component and a p polarization component, wherein the anti-reflective coating is configured to reduce phase retardation between the two components such that an angle of incidence of the s component is substantially similar to that of the p component through the waveguide for a select color of the light. Figure 3 CDJ CDJ CD 4 Co) C-4 _N ":t ___ C4 CNJ C'4