0.98-MU-M INGAAS-INGAASP-INGAP GRIN-SCH SL-SQW LASERS FOR COUPLING HIGH OPTICAL POWER INTO SINGLE-MODE FIBER

A CW coupled optical power of 75 mW into a single-mode fiber (SMF) at a driving current of 200 mA was achieved by InGaAs-InGaAsP-InGaP GRIN- SCH SL-SQW ridge waveguide lasers emitting at 0.98 mum. The GRIN-SCH p rofile was optimized to minimize the series resistance due to spikes a t GaAs-InGaP heterointerfaces. The other approach was proposed for hig h coupling efficiency into the SMF with cutoff wavelength of 0.88 mum: The ridge mesa width was precisely controlled around 2 mum, and an as pect ratio of far-field pattern (theta(perpendicular-to/theta(parallel -to)) was reduced down to 1.9. As a result, 0.98 mum InGaP cladding la sers show performance comparable to the conventional AlGaAs cladding l asers.