Narrow Results

Here we discuss interaction of a single two-level atom with a single mode of interacting electromagnetic field in the Jaynes–Cummings model with the rotating wave approximation.

This paper presents a comprehensive investigation on Kerr nonlinearity in a three-level semiconductor quantum well (SQW) superlattice and validates the existence of large Kerr nonlinearity of the order of $10^4{\mathrm{\text{W}}}^{-1}{\mathrm{\text{m}}}^{-1}$ in the vicinity of an electromagnetically induced transparency (EIT) window. The Kerr nonlinearity is found to vary with the relative phase of the applied optical fields, and by selecting suitable relative phases, an enhanced Kerr nonlinearity can be obtained. The results may find significant applications in optoelectronic and photonic devices.

The interaction of a mesoscopic system of coherently injected two-level Rydberg atoms with a coherently driven single cavity mode is treated outside the rotating wave approximation (RWA). The additional first harmonic component of the output field (outside RWA) exhibits closed hysteresis loops and multiple-switching processes, compared with the hysteresis cycles for the nonoscillatory (fundamental) component within the RWA. This is achieved via two controls: (i) varying the coherent population excitation and relative phase parameters (θ, ϕ) of the coherently injected atoms, and, (ii) varying simultaneously atom and cavity detuning parameters.

In this paper, we investigate numerically the modeled density matrix equations for the interaction of a three-level atomic system in V-configuration with a train of chirped optical n-pulses (up to n = 10) within and without the rotating wave approximation. For adopted data of Rb⁸⁷, maximal population transfer to either of the upper levels is achieved with n > 1 pulse via variation of chirp parameter/frequency mismatch of the closely lying upper levels. Optimal steady population transfer and maximum atomic coherence of the upper levels are predicted for non-zero chirp parameter and train of n = 1 - 10, 30 pulses.

In this paper, we investigate the nonlinear dynamical behavior of dispersive optical bistability (OB) for a homogeneously broadened two-level atomic medium interacting with a single mode of the ring cavity without invoking the rotating wave approximation (RWA). The periodic oscillations (self-pulsing) and chaos of the unstable state of the OB curve is affected by the counter rotating terms through the appearance of spikes during its periods. Further, the bifurcation with atomic detuning, within and outside the RWA, shows that the OB system can be converted from a chaotic system to self-pulsing system and vice-versa.

Optical bistability (OB) for a homogeneously broadened two-level atomic system in a ring cavity is investigated within and without the rotating wave approximation (RWA) using nonautonomous Maxwell–Bloch equations subject to a time delay. It is shown that the dynamics both within and without the RWA are susceptible to the introduction of time delays in the differential equations. A range of instability scenarios are found as certain parameters are ramped up and down and these can affect the bistable operation of the physical devices. However, the introduction of a time delay can also result in an important positive application; for the first time, as far as the authors are aware, it is shown that a type of butterfly hysteresis can occur in the fundamental component, which is a relatively strong output signal, and may be desired in optical signal processing.

In this paper, we treat the Law's effective Hamiltonian of the dynamical Casimir effect (DCE) in a cavity and construct an analytic approximate solution of the time-dependent Schrödinger equation under the general setting through a kind of rotating wave approximation (RWA). To the best of our knowledge this is the finest analytic approximate solution.