INFLUENCE OF A STRONG ELECTROMAGNETIC WAVE ON THE QUASIENERGY SPECTRUM OF A SEMICONDUCTOR.

A model of two parabolic bands is utilized to consider a semiconductor subjected to two intense electromagnetic waves, one of which produces intervand transitions (allowed for in a resonance approximation) and the other, whose frequency is low compared with the band gap, produces only intraband carrier motion. The quasienergy spectrum is calculated. The ″intraband″ wave gives rise to a system of band gaps whose widths oscillate with the wave amplitude. The width of a given band gap may depend nonmonotonically on its serial number.