The present invention aims to provide a wavelength converter capable of stably obtaining a W-class high-output green laser beam and a 2D image display device using this wavelength converter.By causing a polarization direction of a laser light source for generating an excitation light and that of a light emitted from an oscillator to orthogonally intersect, the deterioration of an excitation light source by an ASE is suppressed by a polarization splitting element provided between a laser resonator and the laser light source.