Patent ID: 6862131

Claim:
A laser light generating apparatus, comprising: a laser light source configured to output a laser light of a first wavelength; a phase modulator, to which a modulating signal of different frequencies is applied, disposed on an optical path between the laser light source and a first resonator; a signal generating unit configured to generate the modulating signal applied to the phase modulator; the first resonator and a second resonator disposed in a stage succeeding the first resonator, the laser light outputted from the first resonator being inputted to the second resonator without passing through any phase modulator; a nonlinear optical element disposed in the first resonator; means for changing an optical path length of an optical path of each of the resonators; at least one photodetector configured to receive the laser light from each of the resonators; and a control circuit having a negative feedback configuration configured to obtain an error signal, from at least one light detection signal obtained by the at least one photodetector and the modulating signal, and configured to control the means for changing an optical path length by an FM sideband method using the error signal, wherein the laser light is inputted to the phase modulator, subjected to phase modulation, and then inputted to the first resonator, and light generated by the nonlinear optical element is inputted to the second resonator, and wherein the laser light from each of the first resonator and the second resonator is detected by the at least one photodetector, and the optical path length of each of the resonators is controlled on the basis of the error signal, whereby the resonators are or can be simultaneously held in a resonant state.