Optical Switch Based on Dressed Intracavity Dark States

Abstract

We present a scheme to realize two-direction optical switch by a single-mode optical cavity containing some four-level atoms. The high switching efficiency can be obtained through low photon loss and large third-order nonlinear susceptibility of this N-type atomic system in cavity. Without the microwave source, it can be reduced to a -type atomic system where a coupling laser is used to realize single intracavity electromagnetically induced transparency (EIT). Namely, the probe field can be transmitted almost totally at resonance. Thus a two-direction optical switch is operated and the state for forward (backward) direction is set as "open" ("closed"). When microwave source is introduced, dressed splitting of intracavity dark state happens. The probe field is reflected almost completely at resonance and the state of the optical switch at forward and backward directions (transmitted and reflected channels) is shifted as "closed" and "open", respectively. Moreover, this scheme is much advantageous to realize splitting of intracavity dark state because weak microwave field ( m ∼ 0.1γ 14 ) induces the coupling between intracavity dark state and one sublevel of ground state. While a strong pump laser ( d ≥ γ 14 ) which couples the intracavity dark state with an excited level is applied to realize this splitting in ref. [Phys. Rev. A 85 013814 (2012)].

Electromagnetically induced transparency via localized surface plasmon mode-assisted hybrid cavity QED

“…Referring to the results in Ref. [43], we have already given a general explanation of VF-EIT by adding an extra field so as to enrich the coupling process. This system of Guo et al studied an N-type fourlevel QE and discussed the contribution of a microwave field added to couple the two ground states.…”

“…In previous theoretical research on cavity QED systems, the ideal switching contrasts have been achieved in more complex systems such as a coupled-resonator array (the number is 7) [13] and three empty cavities [12] as the cavity, or a multiple-level quantum emitter (energy level> 3). [43] Wang et al demonstrated that only at a certain probe light-QE detuning and coupling strength, the resonant photons are completely reflected and the cavity QED system could be regarded as a…”

“…6(b). The destructive interference between two coherent excitation paths of the QE ( |2 ⟩ ± |3 ⟩) seen in the conditional EIT effect is induced due to the same strength and opposite phase [43] at the frequency of probe resonance. However, the third coherent pathway is formed due to mode-enhanced factor J between |1, 0, 1 ⟩ and |0, 1, 1 ⟩.…”

Phase‐Dependent Quantum Correlation in a Cavity‐Atom System

“…Especially, it is becoming more and more important to realize and modify intracavity EIT [10][11][12][13][14][15][16][17] in cavity quantum electrodynamics (cavity-QED) systems [18,19]. Comparing with intracavity EIT itself, the modified intracavity EIT has more advantages on light controlling light system, such as low light intensity of switching field and high switching efficiency [12,13,20,21].…”