A possible model for sustained oscillations (pulsations) in (Al,Ga)As double-heterostructure lasers

A model explaining the origins of sustained oscillations in (Al,Ga)As double-heterostructure lasers is proposed and plausibility arguments of its applicability are given. The model relies on saturable-absorber -switching to produce the pulsations, with the saturable absorption located near the ends of the laser in regions where surface recombination reduces the injected-carrier density. The sides of the active volume, or defects which cause carrier recombination within the active volume, may also cause such pulsations according to this model.