Patent ID: 7822300

Claim:
A pixel cell comprising: a photo-conversion device formed in association with a substrate; a plurality of material layers over said substrate; and an anti-resonant reflecting optical waveguide structure formed over said photo-conversion device and within said plurality of material layers, said waveguide structure comprising: a trench within at least a portion of said plurality of material layers; at least three cladding structures formed along a sidewall of said trench, the at least three cladding structures being contiguous along at least the entire length of said trench sidewall; and a core material formed over the at least three cladding structures and filling a remaining portion of said trench, wherein a refractive index of said core material is lower than a refractive index of a first cladding structure in contact with said core material, and wherein a refractive index of a second cladding structure in contact with said first cladding structure is lower than said refractive index of said first cladding structure.