Intersubband absorption in semiconductor quantum wires

Intersubband absorption in semiconductor quantum wires is analyzed within the framework of the position dependent effective mass theory. Selection rules for the optical transitions in rectangular quantum wires are derived based on the symmetry considerations. Bound-bound transitions are next treated. Special attention is devoted to the influence of the self-consistent potential on the absorption profile. It is found that the peak of the effective wire width (appropriate quantity for a system with two-dimensional confinement) is not essentially influenced by the the potential due to electron redistribution, while the peak is lowered by approximately 20%. Similar calculation is performed for bound-free optical transitions. Two distinct peaks originating from the transitions from ground or excited states to continuum are clearly noticed.