Patent ID: 7665891

Claim:
A differential temperature sensor system comprising: a light generating device capable of generating a beam having a carrier frequency; a modulator being driven by a radio frequency and arranged in optical communication with the beam such that the modulator is capable of modulating the beam with a sideband frequency; an optical resonator capable of supporting ordinary and extraordinary modes and arranged in optical communication with the beam downstream from the modulator; an ordinary mode-lock setup capable of locking the carrier frequency of the beam to the ordinary mode of the optical resonator; an extraordinary mode-lock setup capable of locking the sideband frequency of the beam to the extraordinary mode of the optical resonator by providing a specific radio frequency to the modulator substantially corresponding to a frequency shift between the ordinary mode and the extraordinary mode of the optical resonator resulting from a temperature change of the optical resonator; and a processor arranged to receive the specific radio frequency and capable of calculating the differential temperature of the optical resonator based upon the frequency shift between the ordinary mode and extraordinary mode of the optical resonator.