Patent ID: 8199396

Claim:
A laser light source, comprising: an excitation light source; a wavelength converting element made of a non-linear optical crystal and having multiple optical paths along which excitation light from the excitation light source passes, the wavelength converting element generating output light having a first temperature characteristic and adapted to be emitted to the exterior of the laser light source and reference light having a second temperature characteristic different from the first temperature characteristic, by converting the excitation light passing through the optical paths into wavelength converted light; a reference light measuring section for measuring the reference light; and a control section for controlling a temperature of the wavelength converting element based on the reference light measured by the reference light measuring section, wherein the wavelength converting element includes a cyclic polarization inversion structure, and a polarization inversion cycle of the cyclic polarization inversion structure on the optical path of the excitation light for generating the reference light is different from a polarization inversion cycle on the optical path of the excitation light for generating the output light.