Optical gain characteristics in 1.55-μm GaAsSbN/GaAs quantum well structures

The optical gain characteristics in 1.55-mu m GaAsSbN/GaAs quantum-well (QW) structures are investigated using the multiband effective mass theory and the non-Markovian gain model. The results are compared with those of 1.55-mu m InGaNAs/GaAs QW structures. The optical gain of the GaAsSbN/GaAs QW structures is found to be very similar to that of the InGaAsN/GaAs QW structures. The threshold carrier density is estimated to be 190 A/cm(2) for both QW structures for a cavity length of 1000 mu m. On the other hand, the InGaSbN/GaAs QW structures are found to require much smaller N composition than the InGaNAs/GaAs QW structure in order to obtain a wavelength of 1.55-mu m. Hence, lasers of good quality operating at a 1.55-mu m wavelength are expected to be obtained by using InGaSbN alloys because of the low N composition.