Patent ID: 6370170
Filing Date: 2002-04-09
Classification: H01S

Abstract:
An apparatus for laser frequency stabilization, comprising:a laser with an output, the laser having a desired frequency and providing an optical signal at the output of the laser, the optical signal including a substantial frequency chirp signal; a modulator coupled to the laser, and that provides a modulation signal for modulating the laser; a derivative module coupled to the modulator, and that provides a derivative signal which is a time derivative of the modulation signal; a Fabry-Perot etalon coupled to the output of the laser, the etalon having a frequency response including a plurality of resonances, one of the plurality of resonances being centered on the desired frequency; a photodetector coupled to the etalon and that provides a photocurrent in response to a filtered optical signal; a balanced mixer coupled to the photodetector and to the derivative module, and that provides a mixed signal from the photocurrent and the derivative signal; a signal processing module coupled to the balanced mixer, and that provides an error signal which is a time average of the mixed signal; and a feedback control module coupled to the signal processing module and the laser, and that receives the error signal.