Patent ID: 7450800

Claim:
A method of modifying the resonant frequency of a microcavity comprising: providing a plurality of dielectric microcavities; and introducing a permanent resonant frequency alteration to at least one of the said dielectric microcavity, wherein the permanent resonant frequency alteration has been introduced to at least one of the said dielectric microcavity by lithographically forming a secondary dielectric structure within the optical evanescent field of the said microcavity, said secondary dielectric structure does not come into contact with any of said dielectric microcavities; wherein at least one of the said dielectric microcavities is a dielectric waveguide in a closed loop forming a traveling wave resonator; wherein the said secondary dielectric structure is formed along the dielectric waveguide but not in contact with the dielectric waveguide; the secondary dielectric structure being non-guiding for optical frequencies below the cutoff frequency of the second transverse electric (TE) mode of the dielectric waveguide; and the secondary dielectric structure being positioned along the dielectric waveguide as to create a substantially equal perturbation of the evanescent field of the first TE mode of the dielectric wave guide, along the dielectric waveguide.