Patent ID: 7965916

Claim:
A laser light source device, comprising: a fiber laser portion having a first double clad fiber doped with a rare earth as a laser active substance, a second double clad fiber in which is formed a pair of fiber gratings to determine an oscillation wavelength of the first double clad fiber, and a laser light source emitting pumping light to the first double clad fiber to pump the first double clad fiber; a fiber amplifier portion formed of a double clad fiber doped with a rare earth as a laser active substance and amplifying oscillation light of the fiber laser portion; and a wavelength conversion module converting the oscillation light amplified by the fiber amplifier portion to higher harmonics, wherein: the fiber laser portion, the fiber amplifier portion, and the wavelength conversion module are disposed sequentially in this order; the fiber laser portion pumps the fiber amplifier portion by emitting to the fiber amplifier portion the pumping light remaining in the first double clad fiber on which the pumping light of the laser light source has been incident; and the fiber laser portion further has a third double clad fiber in which is formed a polarization portion that transmits only a particular polarization component of oscillation light of the first double clad fiber on a light-exiting side of the first double clad fiber.