Two-state operation of high-power semiconductor lasers with a thick quantum well

We have examined the two-state operation process of the high-power edge-emitting lasers based on AlGaAs/InGaAs/GaAs heterostructure with a thick (90 A) quantum well in the active region. It has been demonstrated that the laser emission spectrum can be switched between spectral lines corresponding to different optical transitions between the quantum states in the active region. The switching process is governed either by pump current or by temperature. The dynamic characteristics of the switching laser pumped with 100 ns current pulses have been investigated and explained. It has been shown that the current density dependence of internal optical loss can cause the current-initiated switching. The temperature impact is much more important and consists in the charge carrier redistribution in the quantum well. The registered optical power near the switching point was near 2 W in continuous wave and 15 W in pulse mode of operation.