Patent ID: 6687269
Filing Date: 2004-02-03
Classification: H01S

Abstract:
A laser apparatus, comprising:a gain medium pumped to emit a plurality of photons in response to an electrical input; a laser cavity, optically coupled to the gain medium, in which said plurality of photons resonate in accordance with a plurality of lasing modes; a signal generator, to generate an excitation signal having varying frequencies; a cavity optical length actuator to vary a cavity optical path length of the laser and responsive to the excitation signal to induce corresponding intensity perturbations in an optical beam produced by the laser; a sensor operatively coupled to sense the intensity perturbations in the optical beam and to generate a response signal corresponding to the intensity perturbations; a phase compensator to add a frequency dependent phase shift to the excitation signal to create a phase-shifted excitation signal that is synchronized with the response signal; and a combiner coupled to combine the phase-shifted excitation signal and the response signal to generate an error signal.