Lasing system with wavelength-conversion waveguide

A lasing system of a wavelength-conversion waveguide type, comprising:

• a self-sustained pulsation type semiconductor laser light source having an emitting portion for emitting a semiconductor laser light with TM (transverse magnetic)-mode oscillation from said emitting portion of said semiconductor light source by self-sustained pulsation;
• a wavelength-conversion waveguide having an incident portion for converting the emitted semiconductor laser light into a second harmonic light and for propagating said emitted semiconductor laser light;
• a focusing lens for focusing said semiconductor laser light emitted from said semiconductor laser light source on said incident portion of said wavelength-conversion waveguide at a Brewster angle;
• and
• an external resonator composed of a couple of reflecting mirrors for resonating said semiconductor laser light emitted from said semiconductor laser light source,
• said self-sustained pulsation type semiconductor laser light source arranged so that the direction of polarization of said semiconductor laser light emitted from said semiconductor laser light source in the TM mode is in alignment with the direction of TM mode of said wavelength-conversion waveguide,
• wherein said semiconductor laser light emitted from said semiconductor laser light source arrives at said incident portion of said wavelength-conversion waveguide with the Brewster angle, thereby producing an improved lasing system generating short-wavelength second harmonic light such that semiconductor laser oscillation threshold current and differential efficiency do no increase.