Strained layer SCH SQW InGaAs/GaAs lasers for 980-nm band

Strained layer InGaAs/GaAs SCH SQW (separate confinement heterostructure single quantum well) lasers were grown by a molecular beam epitaxy (MBE). Highly reliable CW (continuous wave) 980-nm, broad contact, pump lasers were fabricated in stripe geometry using Schottky isolation and ridge waveguide construction. Threshold current densities of the order of J_th ≈ 280 A/cm² (for the resonator length L = 700 μm) and differential efficiency η = 0.40 W/A (41%) from one mirror were obtained. The record wall-plug efficiency for AR/HR coated devices was equal to 54%. Theoretical estimations of above parameters, obtained by numerical modelling of devices were J_th = 270 A/cm² and η = 0.47 W/A from one mirror, respectively. Degradation studies revealed that uncoated and AR/HR coated devices did not show any appreciable degradation after 3000 hr of CW operation at 35°C heat sink temperature at the constant optical power (50 mW) conditions.