Patent ID: 7929589

Claim:
An optical device, comprising: an optical resonator structured to support a whispering gallery mode circulating in a plane of the optical resonator; and a diffractive grating coupler located adjacent to and optically coupled to the optical resonator, the diffractive grating coupler comprising: a fiber comprising a fiber core and a fiber cladding surrounding the fiber core, wherein the fiber core comprises a fiber grating section configured to diffract guided light in the fiber core into the fiber cladding toward the an end facet of the fiber, and wherein the fiber is located to place the end facet adjacent to a surface of the optical resonator to provide optical coupling with the optical resonator; and a phase-type diffractive grating formed on the end facet to evanescently couple light between the fiber and the optical resonator, wherein the diffractive grating is structured to suppress diffracted light in a zero diffraction order and diffract light of the input optical beam into light in at least one of two first diffraction orders that matches in phase with the whispering gallery mode inside the optical resonator.