Multilayer $GaAs-AlAs$ heterostructure laser pumped transversely by an electron beam

An experimental investigation was made of the influence of various types of multilayer $GaAs-AlAs$ heterostructure isotypically doped with $Zn$ or $Te$ on the threshold current of a laser pumped transversely by an electron beam in the energy range 10-40 keV. The best results were obtained for a three-layer $p$-type structure in which the active layer was situated between two wide-gap layers and the structure was pumped through one of these layers. The lowest threshold current density for an electron beam energy of 40 keV was 0.08 A/cm${}^2$ at $T=85$ degree K and 1.3 A/cm${}^2$ at 300 degree K.