Patent ID: 7961378

Claim:
A wavelength conversion light source apparatus, comprising: a fundamental wave light source configured to emit a fundamental wave; a nonlinear crystal configured to convert a wavelength of the fundamental wave by being irradiated with the fundamental wave and making the fundamental wave pass therethrough; a movement unit configured to place the nonlinear crystal thereon and continuously move the nonlinear crystal within a plane, where a phase matching condition is not violated, so that a passage path of the fundamental wave passing through the nonlinear crystal is changed; and a probe light source configured to emit a probe light with a wavelength different from the wavelength of the fundamental wave, wherein the nonlinear crystal is irradiated with the fundamental wave at a first irradiation position and is irradiated with the probe light at a second irradiation position that precedes the first irradiation position in a movement pathway, at a same time, while the nonlinear crystal is moved, a potentially deteriorated portion of the nonlinear crystal, where a wavelength converted output decreases, is specified before the potentially deteriorated portion is irradiated with the fundamental wave, by passing the probe light through the second irradiation position of the nonlinear crystal, and the nonlinear crystal is moved, so that deterioration at the potentially deteriorated portion of the nonlinear crystal is avoided.