ADVANCED 1.55-MU-M QUANTUM-WELL GAINALAS LASER-DIODES WITH ENHANCED PERFORMANCE

The fabrication and characteristics of advanced 1.55 mum quantum-well GaInAlAs laser diodes are presented. The strained layer laser structures were grown by metal organic vapor phase (MOVPE). By employing InP-cladding layers and an etch-stop layer, ridge-waveguide lasers with different longitudinal resonator types were processed by conventional chip technology. The following characteristics have been obtained, which mostly represent best values for 1.55 mum GaInAlAs laser diodes: for Fabry-Perot (FP) lasers, cw operation at 130-degrees-C and a characteristic temperature of 95 K were observed; maximum output power was 46 mW; and the 3 dB bandwidth as high as 17 GHz. Gain-coupled distributed feedback (DFB) lasers with an absorptive grating show a single-mode yield about 75 %, their 3 dB bandwidth being 11 GHz. Two-section gain-coupled DFB devices were continuously tunable over 3 nm. For negatively detuned index-coupled DFB devices an ultrahigh 3 dB bandwidth of 18.5 GHz was measured. All these characteristics are comparable to those of 1.55 mum InGaAsP ridge-waveguide lasers. We report for the first time, the broad-area folded-cavity surface-emitting lasers using GaInAlAs which exhibit a threshold current density of 2 kA/cm2.