Power hysteresis and waveguide bistability of stripe quantum-well InGaAs\/GaAs\/GaAIAs heterolasers with a strained active layer

A study was made of quantum-well injection lasers with a strained active InGaAs layer, emitting at 980 nm. At room temperature the minimum threshold current density for a layer 6 — 7 nm thick was 120 A cm^–2 in a cavity 540 μm long. Phenomena which accompanied the disappearance of the index-guiding lateral confinement because of the ‘anti-index-guiding’ influence of excess carriers were studied in stripe laser diodes of the ridge-wave-guide type. These phenomena included collapse and bistability of lasing, power hysteresis, and changes in the angular distribution. Calculations were made of the mode gain in ridge-waveguide lasers with different geometric parameters and as a function of the excess carrier density. It was found that the mode gain could have a maximum and then fall significantly on increase in the pumping rate, which was used to account for the collapse of lasing and for the power hysteresis.