Quantum wire intersubband emitter

A quantum cascade emitter structure is suggested that is based on electronic transitions in an artificial band structure of coupled quantum wires in contrast to the conventional quantum layer systems. The electron transport is normal to the wires in a $\mathrm{GaAs}/{\mathrm{Al}}_x{\mathrm{Ga}}_{1-x}\mathrm{As}$ heterostructure produced by the cleaved-edge overgrowth method. For a realistic system of this type, the relevant rates of radiative transitions and of nonradiative transitions mediated by longitudinal optical phonons have been calculated and have been compared with corresponding data for quantum cascade emitters based on layered structures.