Broadband coherent perfect absorption by cavity coupled to three-level atoms in linear and nonlinear regimes

Abstract

A broadband coherent perfect absorption (CPA) scheme consisting of an optical resonator coupled with three-level atoms excited by single cavity mode is proposed and analyzed. We show the output light field from the system is completely suppressed under specific conditions when the system is excited in linear and nonlinear regimes by two identical light fields from two ends of optical cavity. An analytical broadband CPA criterion for central and sideband excitations of cavity quantum electrodynamics (CQED) system is derived in linear regime. Moreover, we show the resonant excitation criterion for CPA is greatly extended in nonlinear regime. A new type of bistability behavior is found. The output field intensity and the bistability curve can be well tuned by dynamically adjusting system parameters. Our results demonstrate that the CPA is quite universal, and it should be useful in a variety of applications in optical logic and optical communication devices.

Interaction-free bidirectional multi-channel all-optical switching in a multi-level coupling atom–cavity system

“…is the probability amplitude of atom in state i ), the steady-state solutions of cavity input-output can be obtained. Similar to the case of linear regime, the CPA can be observedin the nonlinear regime of the CQED system [12,26]. Fig.…”

“…L denotes the quantum superoperator. The CQED system is excited in linear regime when the intensity of signal light field in I is weak [11,12]. The optical pumping effects for atoms from ground state to excited states can be neglected in this case, i.e.,…”

“…The output fields from two sides of the CQED system are derived as [13,28]: Other parameters are     [11]. Two output fields at two ends of CQED system are equal when the input fields are identical, , r l out a a  [12,13]. Without the contro light, CPA occurs when the CPA criterion c g N   is met (see Eq.…”

“…N  . The CQED system is then driven into the nonlinear regime [11,12]. Solving the nonlinear Schrödinger equation…”