Abrupt switching and hysteresis of transmittivity of an ultrathin film consisting of J-aggregates

A theoretical study of transmittivity of an ultrathin film (of thickness sm aller than an optical wavelength) comprized of linear molecular aggregates is carried out. We report on an abrupt change of transmittivity of the film at a certain magnitude of the incident field. The effect originates from t he coupling of aggregates via the emitting field. Estimates of driving para meters show that such well-studied objects as J-aggregates of polymethine d yes provide a real basis to realize it, (C) 1999 Elsevier Science B.V. All rights reserved.