| abstract |
A light source device (31,31A) includes: a laser light source (311) emitting a laser beam of a prescribed wavelength; a nonlinear optical element (312), disposed facing a light emergence surface of the laser light source, which converts an emission wavelength of the laser beam emitted from the laser light source and causes the laser beam to emerge; a volume phase grating (313), disposed facing an emergence surface of the laser beam of the converted wavelength converted by the nonlinear optical element, which has formed in an interior thereof a Bragg grating structure (313A) which selectively reflects a laser beam of an emission wavelength; and a first dielectric multilayer (313B), provided on a light emergence surface of the volume phase grating, which transmits the laser beam of the converted wavelength and reflects the laser beam of the emission wavelength. |