A laser light source device includes: a laser light source that emits a laser light; and an optical wavelength conversion section that includes a ferroelectric material carrying therein a plurality of polarization inversion rows in which a polarization inversion area and a polarization non-inversion area are alternately formed in a predetermined direction, and converts the laser light directed in the predetermined direction into a second harmonic. In the laser light source device, the laser light source is disposed at a fixed position to allow any one of the polarization inversion rows to be positioned on an optical path of the laser light.