Intrinsic optical intersubband bistability and saturation in a quantum well microcavity structure

摘要

On the basis of a local-field theory, the field distribution including third-order nonlinearity in a quantum well microcavity structure is derived, and an expression of intersubband optical absorption is thus obtained. It is found that local-field corrections at certain condition can act as a positive feedback so that a bistability can be established. In a quantum well microcavity structure, by changing the length of the cavity, the angle of incidence, the field confinement and the line widths, one can effectively detune the local-field feedback so that the threshold intensity and the 'S'-type loop of the optical bistability can be modified.