Intrinsic optical intersubband bistability in quantum-well structures: External factor effect

A generalized cubic equation is presented to describe the intrinsic optical bistability (IOB) process in a two-level system within the rotating wave approximation when repopulation of the two levels is governed not only by the incident radiation with changing intensity but also by an additional external factor (X-factor). Numerical simulations are performed for two- and three-quantum-well (QW) systems without and within a microcavity. The obtained results demonstrate that a relatively small change of the X-factor-caused repopulation of the subbands (as in all QWs simultaneously as in only one selected QW) can produce a dramatic effect on the reflectance dependence upon the incident radiation intensity, in particular on the IOB pictures. It is shown that the IOB process (dubbed as the IOBX) can be driven by the cyclic change of the X-factor-caused repopulation of the subbands at a carefully chosen fixed value of the incident radiation intensity. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim