PHOTOCONDUCTING FILM INTEGRATED IN A MAGNETOOPTICAL MULTILAYER STRUCTURE - A NEW WAY TO GET BISTABLE AND UNSTABLE OPERATIONS

TE/TM polarised light reflection from a multilayer structure containin g a magneto-optic and a photoconducting film is investigated theoretic ally. A metal film is used whose thickness is chosen to support long-r ange surface plasmons. This is to use their sharp resonance for tuning the whole structure. The off-diagonal elements of the dielectric tens or are epsilon(12) = -epsilon(21) = ig and these can be switched from g = 0.05 to g = -0.05. Light tunnelling in the photoconducting layer c auses the appearance of a current that can re orient the magnetisation from M to -M (g = -0.05). The switching occurs at 0.5 mW given an ini tial value g = 0.05. The back re orientation -M --> M, as the light in tensity is reduced, occurs at only 0.1 mW. Hence it is shown that TE r eflected light will exhibit a novel bistable dependence.