1.55-MU-M DFB LASERS INCORPORATING ETCHED LATERAL TAPER SPOT SIZE CONVERTERS

The authors describe the fabrication and characterisation of 1.55 mu m wavelength DFB lasers with integrated, etched lateral taper, spot siz e converters. The buried ridge structure lasers were fabricated by con ventional two-stage growth and processing techniques. Typical threshol d currents of 10-15mA were achieved with output powers up to 25mW at 1 00mA drive and with high singlemode yield. Coupling efficiencies to si nglemode fibre were similar to 40% with positional tolerances of appro ximately +/-2 mu m at the -1dB power point.