A simple approximation for high-temperature properties of the injection laser

The purpose of this paper is to derive simple approximations for the threshold current, gain, and lasing frequency of the GaAs injection laser at or near room temperature. This latter requirement implies that these properties are largely due to effects arising from the parabolic bands in the active region rather than the heavily-doped band `tails'. Thus a parabolic band approximation is employed together with the assumption of an effective energy gap to take account (at least qualitatively) of the high doping.