Patent ID: 6944194

Claim:
A light wavelength conversion module comprising: (a) a light wavelength conversion element formed of a bulk-shaped wavelength conversion crystal, said light wavelength conversion element being for converting a wavelength of a fundamental wave, said light wavelength conversion element having an end surface; (b) a semiconductor laser for emitting a laser beam for entering said light wavelength conversion element as the fundamental wave; and (c) a transmission type wavelength selecting optical element disposed between said semiconductor laser and said light wavelength conversion element, said wavelength selecting optical element selecting a wavelength of the laser beam which is reflected by an end surface of said light wavelength conversion element and is to be fed back to said semiconductor laser, wherein said wavelength selecting optical element selects a wavelength of the laser beam reflected by the end surface of said light wavelength conversion element, wherein the laser beam enters said light wavelength conversion element at the end surface.