Patent ID: 7991025

Claim:
A laser device, comprising: a laser that is tunable in response to a control signal and produces a laser beam at a laser frequency; and an optical resonator structured to support a whispering gallery mode circulating in the optical resonator, the optical resonator being optically coupled to the laser to receive a portion of the laser beam into the optical resonator in the whispering gallery mode and to feed laser light in the whispering gallery mode in the optical resonator back to the laser to stabilize the laser frequency at a frequency of the whispering gallery mode and to reduce a linewidth of the laser, wherein the optical resonator includes a mechanism internal to the optical resonator that uses received light in the whispering gallery mode circulating in the optical resonator to generate counter-propagating light in the whispering gallery mode which is coupled out of the optical resonator back to the laser, and wherein the internal mechanism of the optical resonator is an optical grating formed at a surface of the optical resonator to interact with the received light in the whispering gallery mode circulating in the optical resonator to generate the counter-propagating light in the whispering gallery mode which is coupled out of the optical resonator back to the laser.