Patent ID: 8743916

Claim:
A plane waveguide type laser, comprising: a substantially plate-shaped laser medium; a semiconductor laser disposed close to one end surface of the laser medium on an optical axis of the laser medium, for inputting excitation light into the laser medium; a first cladding bonded to a lower surface of the laser medium for forming a waveguide in a vertical direction to the laser medium; a second cladding bonded to an upper surface of the laser medium for forming the waveguide in the vertical direction to the laser medium; a heat sink bonded to a lower surface of the first cladding; a wavelength selection waveguide disposed close to another end surface of the laser medium on the optical axis of the laser medium, for reflecting laser light having a predetermined wavelength which is a part of fundamental laser light exiting from the laser medium, and transmitting remaining laser light having other wavelengths; and thermal lens producing means bonded to an upper surface of the second cladding, wherein laser oscillation in the vertical direction is performed in a waveguide mode of the laser medium or the wavelength selection waveguide, wherein the thermal lens producing means forms a periodic thermal lens effect in the laser medium so that laser oscillation in a horizontal direction is performed in a plurality of resonant modes, and wherein the wavelength selection waveguide includes a nonlinear material, and converts the fundamental laser light entering the wavelength selection waveguide into laser light having a different wavelength to output the laser light.