Patent ID: 8917443

Claim:
A wavelength converting device comprising a periodic domain inversion structure for converting a wavelength of a fundamental wave to generate a harmonic wave; said fundamental wave being oscillated from a laser light source, said wavelength converting device comprising a ferroelectric substrate and said periodic domain inversion structure formed in said ferroelectric substrate, said ferroelectric substrate comprising an upper face, a bottom face, an incident face to which said fundamental wave is made incident and an emitting face; wherein a vertical domain inversion boundary of said periodic domain inversion structure is inclined with respect to a normal line of an upper face of said ferroelectric substrate, provided that said ferroelectric substrate is viewed in a cross section parallel with a propagating direction of said fundamental wave and parallel with said normal line of said upper face said vertical domain inversion boundary of said periodic domain inversion structure is inclined with respect to said upper face of said ferroelectric substrate, provided that said ferroelectric substrate is viewed in a cross section perpendicular to said propagating direction of said fundamental wave; and wherein said ferroelectric substrate comprises an off-cut Y-plate.