Performance characteristics of strained layer InGaAs/GaAs broad area and ridge waveguide lasers

Strained layer InGaAs/GaAs single quantum well lasers were fabricated by metal organic vapour phase epitaxy. A broad area threshold current density of 126 A/cm² was measured for the 1200 mu m long devices. Low transparency current density and internal loss were deduced from the study of lasers with different cavity lengths and from using a logarithmic gain-current relation. Variation of the emission wavelength with the cavity length was demonstrated. From this wafer, low threshold ridge waveguide lasers emitting at 984 nm were fabricated that have a potential application as pump sources for erbium doped fibre amplifiers.