We discuss the possibility of using a thin layer of inhomogeneously broadened resonant emitters as a multichannel all–optical switch. Switching time from the lower stable branch of the system's bistable characteristics to the upper one and vice versa, which determines the speed of operation of a bistable device, is studied.
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.
We have developed, ab initio, a theory for the interaction of coherent laser light in three-photon resonance with two effective levels of a multilevel atom. The theory is developed to consider the optical bistability of homogeneously broadened, three-photon, resonant multilevel atoms inside a ring cavity. It is shown that optical bistable behaviour in the fundamental and the generated third harmonic can be obtained using, for example, Na atoms. The device may be useful in constructing two-channel, optical bistable switches. In certain nonlinear regimes it may be possible to obtain reversed switching between the fundamental and the third harmonic bistability.
This Letter is concerned with the parallel operation of optical bistable devices. The two-beam side-by-side case has been simulated numerically. Diffraction coupling from one device operating in the upper branch can cause the other one, operating in the lower branch, to switch to the upper branch if the separation of the two beams is too small. The separation required for independent operation is usually a few beamwidths. The results give promise for performing parallel operations with optical bistable devices on the same étalon.
We report the fastest ON/OFF switching bistable optical device yet demonstrated. The device consists of a 13-μm thick CdS platelet in a Fabry-Perot cavity formed by two external mirrors with 90% reflectivity. Very well-defined OM and OFF states with switching times of < 1 nsec (ON) and 2 nsec (OFF) are observed when the laser frequency is tuned to within about one halfwidth below the inhomogeneously broadened bound exciton resonance in CdS. In Fig. 1, the Input and output pulse forms are shown revealing the fast switching.