LASER LIGHT SOURCE DEVICE, IMAGE DISPLAYING DEVICE, AND MONITORING DEVICE

PROBLEM TO BE SOLVED: To provide a light source device, an image displaying device, and a monitoring device that reduce the cost, have high conversion efficiency by a wavelength converting element even when lights of a plurality of wavelengths come, and reduce the scintillation. SOLUTION: The light source device includes a light source section 2 for emitting lights of the plurality of wavelengths, an optical path converting section 31 for converting the optical path of at least part of light, of the lights of the plurality of wavelengths emitted from the light source section 2, and the wavelength converting element 30 that has a polarization reverse structure where polarizations are reverse mutually and converts at least part of light, of the light emitted from the light source section 2, into a predetermined conversion wavelength. The wavelength converting element 30 is formed so that, of the lights of the plurality of wavelengths emitted from the light source section 2, the pitch of polarization reversal where light with the longest wavelength passes is the longest, and the pitch of polarization reversal where light with the shortest wavelength passes is the shortest. COPYRIGHT: (C)2009,JPO&INPIT