Pulse propagation in an atomic medium under spontaneously generated coherence, incoherent pumping, and relative laser phase

Controlling optical bistability, multistability and all-optical switching through multi-photon excitation process

“…Now we extend our consideration from the steady to a dynamical regime without ring cavity configuration. The dynamic response of the probe field (equation ( 12)) in terms of Rabi frequency is given by [46][47][48][49][50]…”

“…For convenience, we represent Rabi frequency of the probe field by Ω p (z, t) = Ω p0 f (z, t), where Ω p0 is a real constant indicating the maximal value of the Rabi frequency at z = 0 and f (z, t) is a dimensionless spatiotemporal pulse-shaped function. In a co-moving frame with ξ = z and τ = t − z c the wave equation (equation ( 17)) of the probe field can be rewritten as [46][47][48][49][50]…”

“…When the switching field is OFF (i.e. Ω s = 0), the atomic medium is in the Rydberg EIT state and transparent to the probe pulse, hence the probe pulse remains almost unchanged over a long traveling distance (figure 9(a)) [47]. When the switching field is ON, the system goes to the highly absorbing Rydberg EIA state and as a result the probe field gets absorbed.…”

“…On the other hand, all-optical switching has become an essential element in optical communication and information networks due to its high response speed and low switching thresholds. In recent years, all-optical switching has been studied using different multi-level atomic systems [40][41][42][43][44][45][46][47][48][49][50]. Sheng et al reported experimental observation of all-optical switching in an N-type atom-cavity system with a rubidium atomic vapor cell inside an optical ring cavity [43].…”

“…Duan et al reported experimental observation of all-optical switching in a double-Λ type four-level atom-cavity system and also presented a theoretical analysis [45]. Minh et al showed the influences of SGC and relative phase of laser fields on a probe laser pulse propagating in a three-level Ξ type atomic system under incoherent pumping [47]. Recently Xuan et al proposed a model of four-level V-Ξ atomic medium to realize all-optical switching for a probe light in weak and strong probe regimes [50].…”