Optical Bistability and Hysteresis of a Thin Layer of Resonant Emitters: Interplay of Inhomogeneous Broadening of the Absorption Line and the Lorentz Local Field

We investigate conditions for the occurrence of a bistable response from a thin layer of an ensemble of two-level inhomogeneously broadened emitters upon their interaction with resonant radiation. A Lorentz correction to the local field that acts on emitters is taken into account. Bistability phase diagrams in the parameter space (inhomogeneous broadening, detuning away from resonance, and local field) are calculated, and the occurrence of optical hysteresis of the system is demonstrated. In addition to this, we study the switching time from the lower stable branch of the bistable characteristics to the upper one and vice versa against the intensity of the driving field, which determines the operation speed of a bistable device. The possibility of using a thin layer of resonant emitters as a multichannel all-optical switch is discussed