Patent ID: 7542491

Claim:
A wavelength converter, comprising: a laser resonator including a fiber containing an laser-active material and a fiber grating formed in the fiber; a laser light source for emitting an excitation light to the fiber; a polarization splitting element provided between the laser resonator and the laser light source; and a wavelength conversion element for converting a fundamental wave of a laser beam emitted from the laser resonator into a harmonic, wherein: the laser resonator is constructed to emit a beam polarized in a direction normal to a polarization direction of the laser light source using a polarization maintaining fiber and a single polarization mechanism and includes a pair of reflection surfaces; and the polarization splitting element is provided between one of the respective reflection surfaces closer to the laser light source and the laser light source to introduce an excitation light in a specified polarization direction emitted from the laser light source to the laser resonator while introducing the fundamental wave emitted from the laser resonator and having a polarization direction normal to the specified polarization direction in a direction deviated from the laser light source.