Transverse effects in a thin slab of material with local-field induced intrinsic optical bistability

Abstract

We consider a thin slab of dense material exhibiting local-field induced intrinsic optical bistability irradiated by a transversely uniform optical field (holding beam). We study the transverse effects that can arise when local excitations are created by means of a narrow optical beam (writing beam). We show that whereas diffraction effects are negligible, diffusion effects make the excitation-domain walls to move inward or outward in the transverse direction, with a speed that depends on the holding-beam intensity and the diffusion coefficient. Conditions can be found, however, for which the wall movement is counterbalanced by the field transverse gradient so that stable narrow excitation domains can be created that remain after the writing beam has been switched off. Such domains can be read on the transverse profile of the output field and can be erased by means of another narrow beam. Some issues concerning potential applications in optical parallel information processing are discussed.