Patent ID: 7999998

Claim:
A short wavelength light source comprising: a wavelength conversion element for converting a fundamental wave into a harmonic wave, said wavelength conversion element including: an incident surface, to which the fundamental wave is incident; an output surface, from which the harmonic wave is outputted, said output surface being located at a light output side of said wavelength conversion element; and a specific region located at said light output side, said specific region being arranged to suppress variations in phase matching conditions, between the fundamental wave and the harmonic wave, which result from heat generated by absorbing the harmonic wave during a wavelength conversion of converting the fundamental wave into the harmonic wave; and a holder for holding said wavelength conversion element, said holder including: a first heat radiation member holding said wavelength conversion element at a region other than said specific region; and a second heat radiation member holding said wavelength conversion element at said specific region, said second heat radiation member having a higher thermal conductivity than said first heat radiation member, wherein a thickness of said specific region is smaller than a thickness of said other region.