Patent ID: 7522284

Claim:
An optical gyro comprising: a ring resonator having a predetermined optical mode configured to circulate light beams in counter-propagating directions, said ring resonator comprising an optical fiber coil having a hollow core and first and second ends; a first optical element configured to: receive an input light beam; and transmit a portion of said input light beam in a counter-propagating direction of the ring resonator, said portion of said input light beam entering one of said first and second ends of said optical fiber coil; a second optical element configured to: direct together with said first optical element a majority of a circulating light beam in said counter-propagating direction of the ring resonator, said circulating light beam based on said portion of said input light beam; and derive a transmission component of said circulating light beam at one of said first and second ends of said optical fiber coil, said transmission component indicating a resonance peak of said counter-propagating direction of the ring resonator; and a filter coupled between said first and second optical elements, said ring resonator configured to accept via said filter said portion of said input light beam having said predetermined optical mode.