Optical ring resonator sensor

摘要

A sensor is to measure a physical quantity which causes a non-reciprocal effect, such as the Sagnac-effect, in an optical ring resonator. This effect provides a difference of clockwise and counter-clockwise optical path lengths in the ring resonator. The difference is proportional to the physical quantity, such as rotation rate in the case of the Sagnac-effect. A semiconductor laser is coupled to the ring resonator and generates clockwise and counter-clockwise beams therein. The laser frequency is modulated by directly energizing the semiconductor laser such that sidebands of the frequency-modulated laser beams are in resonance with the ring resonator. A detector device responds to the difference of the clockwise and counter-clockwise light beams and generates a signal indicative of the measured physical quantity.