Influence of multiple self-absorption of spontaneous radiation on the threshold pumping rate of heterojunction lasers

An analysis is made of the degree of reduction in the threshold rate of pumping of semiconductor heterojunction lasers as a result of deposition of specularly or diffusely strongly reflecting coatings (metal contacts) directly on relatively thin emitters. An investigation is made of the dependence of this effect on the losses in the passive layers, thickness of the active layer, and impurity concentration in the active layer. It is shown that the threshold pumping rates can be several times lower for lasers of this type than for conventional heterojunction lasers.