POWER HYSTERESIS AND WAVE-GUIDE BISTABILI TY OF STRIPE QUANTUM-WELL INGAAS GAAS/GAALAS HETEROLASERS WITH A STRAINED ACTIVE LAYER/

A study was made of quantum-well injection lasers with a strained acti ve InGaAs layer, emitting at 980 nm. At room temperature the minimum t hreshold current density for a layer 6-7 nm thick was 120 A/cm(2) in a cavity 540 mu m long. Phenomena which accompanied the disappearance o f the index-guiding lateral confinement because of the <<anti-index-gu iding>> influence of excess carriers were studied in stripe laser diod es of the ridge-waveguide type. These phenomena included collapse and bi-stability of lasing, power hysteresis, and changes in the angular d istribution. Calculations were made of the mode gain in ridge-waveguid e lasers with different geometric parameters and as a function of the excess carrier density. It was found that the mode gain could have a m aximum and then fall significantly on increase in the pumping rate, wh ich was used to account for the collapse of lasing and for the power h ysteresis.