Cavity length dependence of the threshold behavior in thin quantum well semiconductor lasers

A theoretical analysis is presented which shows that the threshold current of thin single quantum well injection lasers can be virtually independent of cavity length over a wide range of dimensions, in agreement with experimental observations. In short devices, however, additional nonradiative mechanisms such as Auger processes, recombination from valleys, and carrier leakage become significant and cause a sharp increase of the threshold current as well as a collapse of the quantum efficiency. Discontinuous lasing wavelength shifts toward shorter values are expected as the cavity length is reduced. These features are in marked contrast with the behavior of conventional double-heterostructure devices.