Patent ID: 7054524

Claim:
A slab waveguide comprising a first cladding layer having a first dielectric constant; a photonic crystal layer formed on said first cladding layer, said photonic crystal layer including periodically arranged regions of a first dielectric material within a second dielectric material, each of said periodically arranged regions of said first dielectric material being asymmetric with respect to the mid-plane of said photonic crystal layer, said periodically arranged regions inducing an asymmetry in the mode field distribution of an optical signal propagating within said photonic crystal layer; and a second cladding layer formed on said photonic crystal layer, said second cladding layer having a second dielectric constant, said second dielectric constant differing from said first dielectric constant; wherein the difference between said first and second dielectric constants causes said first and second cladding layers to offset said asymmetry in said mode field distribution in said photonic crystal layer induced by said periodically arranged regions.