Gain spectra and characteristics of a transistor laser with InGaAs Quantum Well in the base

We have calculated the gain spectra of a heterojunction bipolar transistor laser in which a single InGaAs quantum well is embedded in the GaAs base. Effects of strain on band structure, finite barrier height on subband energies, momentum dependent matrix element, bimolecular and Auger recombination in recombination rate and a Lorentzian lineshape function are considered for gain calculation. The gain shows a maximum at the energy separation between the first subbands of heavy hole and conduction band. The calculated transparency current and threshold current are of the same order as in experimental and other theoretical works. A connection between the virtual carrier density and base current calculated from rate equations is established.