CHARACTERIZATION OF AN INGAAS-GAAS-ALGAAS STRAINED-LAYER DISTRIBUTED-FEEDBACK RIDGE-WAVE-GUIDE QUANTUM-WELL HETEROSTRUCTURE LASER

InGaAs-GaAs-AlGaAs strained-layer DFB ridge-waveguide lasers requiring a single MOCVD growth step are shown to operate in a single longitudinal mode up to 2.2 x I(th) with an AR coating applied to one facet under room temperature, pulsed conditions. A value of kappa-L = 0.33 has been determined from threshold gain calculations for coated and uncoated devices. Weak lateral optical confinement, provided by unpumped lateral gratings, is demonstrated by the absence of antiguiding effects, and a real lateral index step of approximately 4 x 10(-3) is determined from near-field emission patterns.