Interacting multiwave mixing in a five-level atomic system

Abstract

We study three ͑nested, parallel, and sequential cascade͒ types of schemes for doubly dressed four-wavemixing processes in an open five-level atomic system. The interaction between two dressing fields of the nested-cascade scheme is strongest and weakest for the parallel-cascade scheme, with the sequential scheme intermediate between them. Mutual-dressing processes and constructive or destructive interference between two coexisting dressed multiwave mixing channels in such a system are also considered. Investigations of these multidressing mechanisms and interactions are very useful to understand and control the generated high-order nonlinear optical signals.

Controlled multi-wave mixing via interacting dark states in a five-level system

“…Several features of this work are distinctly different and gain an advantage over the previously reported MWM processes [20][21][22]. Firstly, multi-dressed FWM, SWM, and EWM processes coexist and compete in a five-level system because FWM is suppressed while SWM and EWM are enhanced by controlling the offsets of fields.…”

“…According to the physics of the perturbation chain, as to certain element denoting a state, only the higher-order element in the chain can contribute to it, the other weak term can be neglected then. Consequently, simplified densitymatrix equations about ρ 10 (1) , ρ 20 (2) and ρ 10 (3) …”

“…That is why it is called as the nested dressing scheme [20,21] and ρ 10 (3) in the chain (F1) can be modified as…”

“…We can see that the dualdressed FWM is actual the interference between the polarizations ρ′ F1 and ρ′ S . In addition, under the weak field limit (|G 3 | 2 bb Γ 10 Γ 30 and |G 4 | 2 b b Γ 10 Γ 14 ), the parallel dual-dressed FWM (DDFWM) can be considered as a coherent superposition of signals from one FWM, two SWM and one EWM processes [20] according to its expression expansion.…”

“…In our recent studies, the third-order and fifth-order nonlinear processes coexist in an open (such as V-type, Y-type and inverted-Y-type) atomic system were demonstrated, in which the coexisting SWM signal can become comparable or even greater than the companion FWM by manipulating the atomic coherence [17][18][19]. After that, three kinds of doubly-dressed FWM processes (in nested, parallel and sequential dressing schemes) were investigated [20][21][22]. Here, we present controlled MWM (FWM, SWM and EWM) via interacting dark states in a five-level system ( Fig.…”