Coherent control of optical bistability and multistability via double dark resonances (DDRs)

We study coherent perfect absorption (CPA) theoretically based on a weakly coupled atom-cavity system with an optically pumped second-order nonlinear crystal (SOC) embedded in the cavity. Our system does not require a strong coupling, which is often needed for CPA in previous studies but is challenging to implement experimentally in some systems. The role of the SOC is to introduce a tunable effective decay rate of the cavity, which can lead to CPA in the weak-coupling regime. The proposed system exhibits bistable behaviors, with bistable patterns switchable between conventional and unconventional shapes. By varying the properties of the SOC, the operation point of CPA can be tuned to be inside or outside the bistable regime. It can also be located at the upper or the lower stable branch or even the unstable branch of the bistable hysteresis loop. It is however robust against the parameters of the SOC for any fixed effective decay rate. Our system can potentially be applied to realize optical devices such as optical switches in the weakly coupled regime.

Coherent perfect absorption in a weakly coupled atom-cavity system

Introducing a dressed-state description, we show that a trapped ion in a standing wave field can be described by a nonlinear Jaynes-Cummings model different from the counterpart of Vogel and Matos Filho [Phys. Rev. A 52 (1995) 4214] in several aspects, which may carry important implications for the preparation and reconstruction of the nonclassical states of a trapped ion.

https://iopscience.iop.org/article/10.1088/0256-307X/15/3/012/pdf

Nonlinear Jaynes-Cummings Dynamics of a Trapped Ion Under a Dressed-State Description

We theoretically investigate the hybrid absorptive-dispersive optical bistability (OB) and optical multistability (OM) behaviors induced by Fano-type interference in a four-subband asymmetric semiconductor double quantum wells scheme driven by a degenerate probe field and a coherent coupling field. We show that the appearance or disappearance of OB can be controlled by modulating the strength of the Fano-type interference. We also present the threshold and hysteresis cycle of the OB can be controlled by adjusting the intensity of the coherent coupling field. Moreover, OB can be switched to OM by tuning the frequency detuning of the coherent coupling field or vice versa. This interesting scheme may provide guidance for technological applications in optoelectronics and solid-state quantum information science.

https://iopscience.iop.org/article/10.1088/1361-6455/aaf601/pdf

Controllable optical bistability and multistability in asymmetric quantum wells via Fano-type interference

Optical bistability (OB) and optical multistability (OM) behaviors induced by multiple spontaneously generated coherence (SGC) are investigated theoretically in a tripod four-level atomic scheme. It is found that OB or OM is sensitive to the SGC effects, and the thresholds of OB can be controlled via changing the strength of multiple SGC or the relative phases of the applied fields. In addition, we can switch OB to OM by adjusting the twofold relative phases of the applied fields or vice versa.

Multiple spontaneously generated coherence and phase control of optical bistability and multistability in a tripod four-level atomic medium.

We have studied a laser system in which initially incoherent atoms are injected into a cavity and directly driven by a coherent pump field. Here we show that such a system can display optical bistability in the absence of population inversion. Two disconnected branches of the solutions are obtained for lasing action. They correspond to the inversion branch and inversionless branch, respectively. Also, a mechanism is proposed here to produce higher-power lasing by the inversionless laser.

Optical bistability and lasing without inversion in a system of driven two-level atoms with incoherent injection

We examine a model of a driven two-level system with injected coherent atoms. We find a set of lasing phase diagrams for the resonant excitations. We show that the laser field in the system is related to the initial preparation of atoms, and that when the degree of this coherence is changed, the system exhibits bistability in the inversionless region. We also discuss the crucial role of atomic coherence in achieving lasing action. \textcopyright{} 1996 The American Physical Society.

Zaiguang Li

Papers

Optical bistability and lasing without inversion in a system of driven two-level atoms with incoherent injection

Atomic coherence and bistable lasers without inversion.