Calculated threshold current of GaAs quantum well lasers

A model calculation of the threshold current of a laser in a quantum well structure is presented. The band-to-band radiative recombination rate is calculated using a constant density of states and the k-selection rule. This calculation shows that the threshold current of a GaAs single quantum well laser has low-temperature sensitivity (T0∼330 K for T>300 K). The calculated threshold current of a 200-Å-wide GaAs single quantum well laser is ∼550 A/cm2. The results of the calculation are compared with experimental results.