Patent ID: 7400797

Claim:
A transverse closed-loop waveguide resonator comprising: an inner cladding having a surface peripherally forming a substantially cylindrical closed-loop shape for confining light to the surface, the inner cladding having a first diameter thickness and a first index of refraction profile in a cross-sectional portion of the transverse closed-loop resonator; and a ringed-core corresponding to the closed-loop shape disposed on the corresponding surface of the inner cladding, the ringed-core being so dimensioned and having a second thickness of material thinner than the first diameter thickness, and a second index of refraction profile greater than the first index of the inner cladding by an index delta in the cross-sectional portion of the transverse closed-loop resonator, such that the ringed-core confines guided light radially within the ringed-core-around the closed-loop shape, the inner cladding having a first average index of refraction for limiting whispering-gallery-modes to have a mode index of refraction lower than the average index of refraction of the inner cladding, the ringed-core surrounding the inner cladding sufficiently thin and having a second average index of refraction greater than the first average index of the inner cladding for supporting an index-guided resonant optical circumferential mode having a mode index of refraction greater then the average index of the first average index of refraction of the inner cladding.