The effects of the incoherent pumping field on the phase control of group velocity

Abstract

This paper studies the effects of the incoherent pumping field and the spontaneously generated coherence (SGC) on the phase control of group velocity. The effects of a relative phase between probe and coupling fields on the absorption and the dispersion are then discussed. It is shown that the phase dependence of the group velocity not only depends on the existence of the SGC, but also depends on the existence of the incoherent pump field. We show that for the weak probe field, and in the presence of SGC, the existence of the incoherent pump field is a necessary condition for the phase control of the dispersion, the absorption and the group index.

Group velocity control in the ultraviolet domain via interacting dark-state resonances

“…A weak coupling field with frequency ω 41 and Rabi frequency g 41 is applied to transition |1 ↔ |4 . The weak probe field with frequency ω 23 and Rabi frequency g 23 = g p couples to transition |2 ↔ |3 . Finally, an incoherent driving field with pump strength Λ is applied to the probe transition.…”

“…Sub-and superluminal light propagation together with nonlinear optical gain or losses were observed in [22]. Two of the present authors suggested to use an incoherent pump field to control light propagation from subluminal to superluminal [23,24]. Recently, we have studied the light propagation of a probe pulse in a four-level double lambda system, where the applied laser fields form a closed interaction loop [25].…”

Large Kerr coefficient via quantum interference induced by incoherent pump field and spontaneous emission

“…Quantum interference arising from incoherent Page 3 of 20 A c c e p t e d M a n u s c r i p t pumping processes has been used for modifying spontaneous emission [31,32], phase dependence of collection fluorescence [33], and coherent population trapping [34]. The effect of incoherent pump field on phase control of group velocity and dynamical behavior of the absorption and dispersion has also been studied [35][36][37].…”

“…It is demonstrated that the combine effect of SGC and quantum interference of incoherent pump field make the system phase dependent; thus the optical properties of the medium such as amplification without population inversion, dispersion, absorption, and group velocity of a weak probe field can be controlled by the relative phase of applied fields [35,38]. In addition, quantum interference of incoherent pump field can dramatically modify the nonlinear response of the medium; thus optical bistability and multi-stability can be controlled by the quantum interference of incoherent pump field and spontaneous emission [39,40].…”

Absorption free superluminal light propagation in a three-level pump–probe system

“…The effect of the incoherent pumping field as well as spontaneously generated coherence (SGC) [14] on controlling the group velocity of probe field has been discussed [15,16].…”