Optimization of SHG for high-brightness semiconductor laser diode radiation with large aberrations
Ferdinand-Braun-Institut für Höchstfrequenztechnik, Berlin
Abstract
The progress in high-brightness semiconductor lasers in the IR range stimulates the direct second harmonic generation (SHG) of their radiation for creation of short wavelength light sources. High-brightness cw-lasers are DFB-lasers, slab lasers, alfa-DFB-lasers, MOPA, tapered lasers and external resonator lasers within the actual power range between 0.4 and 7.7 W. Partially, those lasers show large aberrations, such as elliptical emission and/or strong astigmatism. The optimization of the SHG should take into consideration three items, simultaneously: a SHG-merit function, the residual aberrations of the micro-optics, and possible changes of the design parameters of the lasers. The examples comprise alfa-DFB-lasers and tapered lasers.