VISIBLE LASER SOURCES BASED ON FREQUENCY-DOUBLING IN NONLINEAR WAVE-GUIDES

This paper reviews nonlinear quasi-phase-matching (QPM) waveguides and laser diodes with application to conversion of infrared laser diode w avelengths to the visible. The discussion of nonlinear QPM waveguides includes Ti-diffusion poled and E-field poled LiNbO3 and KTP waveguide s. Up to 25 mW of blue output power has been demonstrated for 120-mW i nfrared power injected into a nonlinear waveguide. Semiconductor laser sources suitable for frequency doubling are discussed, including dist ributed Bragg reflection (DBR) lasers operating at up to 200 mW output power, master oscillator power amplifiers with over 1 W output power, and wavelength-tunable hared semiconductor lasers with over 0.5 W out put. A compact blue laser with 1-4 mW output power at 425-nm wavelengt h has been demonstrated based on a DBR laser frequency-doubled in a no nlinear waveguide.