Topic
Atomic coherence
About: Atomic coherence is a research topic. Over the lifetime, 877 publications have been published within this topic receiving 29395 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: The essential condition for three-photon electromagnetically induced absorption (TPEIA) in a Doppler-broadened ladder-type atomic system is reported and it is found that an atomic group with a proper velocity for ladder- type TPEIA should satisfy the one-photons of all three optical fields.
Abstract: We report the essential condition for three-photon electromagnetically induced absorption (TPEIA) in a Doppler-broadened ladder-type atomic system. When the two coupling lasers operate at different frequencies, we observed Doppler-free TPEIA resonance at a counterintuitive frequency, which is the almost half-frequency detuning of the frequency difference between the two coupling fields. Considering three-photon coherence in a Doppler-broadened ladder-type three-level atomic system, the TPEIA due to the atomic group of non-zero velocity was in good agreement with the calculated TPEIA spectrum under the one-photon resonance condition of all three optical fields. From the results, we found that an atomic group with a proper velocity for ladder-type TPEIA should satisfy the one-photon resonances of all three optical fields.
5 citations
TL;DR: In this article, the feasibility of attaining simultaneous electromagnetically induced transparency (EIT) and efficient nonlinear generation in different configurations of Doppler broadened diamond (double-cascade) systems such as, the frequency up-conversion, nearly degenerate and degenerate scheme was explored.
Abstract: We explore the feasibility of attaining simultaneous electromagnetically induced transparency (EIT) and efficient nonlinear generation in different configurations of Doppler broadened diamond (double-cascade) systems such as, the frequency up-conversion, nearly degenerate and degenerate scheme. We show that EIT and nonlinear generation efficiency depend critically on the type of residual Doppler broadening present in each of the two cascade subsystems constituting the diamond system. Furthermore, it is observed that nonlinear generation with perfect EIT simultaneously in both subsystems is not possible as the process of nonlinear generation actually tends to oppose EIT. Yet in an extended medium, on resonance field propagation under matched conditions for probe and generated signal can occur when a balance (equilibrium) is established between these two competing processes.
5 citations
TL;DR: In this article, the photonic bands of an atomic Bose-Einstein condensate with a triangular vortex lattice were investigated, and the frequency-dependent dielectric function was used in the calculations, resulting in photonic band gap widths of a few megahertz.
Abstract: Received 26 March 2007; published 27 June 2007We investigate the photonic bands of an atomic Bose-Einstein condensate with a triangular vortex lattice.Index contrast between the vortex cores and the bulk of the condensate is achieved through the enhancementof the index via atomic coherence. The frequency-dependent dielectric function is used in the calculations ofthe bands, resulting in photonic band gap widths of a few megahertz.DOI: 10.1103/PhysRevA.75.063627 PACS number s : 03.75.Lm, 42.50.Gy, 42.70.Qs, 74.25.Qt
5 citations
TL;DR: In this article, the authors consider the response of a coherent population-trapping (CPT) signal to a sudden, step-function change in laser polarization and find that the transient behavior depends on both the redistribution of atomic population among the atom's Zeeman sublevels and the regeneration of atomic coherence between these sublevels.
Abstract: In ultraminiature atomic physics (UAP), where the goal is to perform low-power, 'chip-scale' precision spectroscopy, stochastic-field/atom interactions can play a primary role in defining the limits of sensitivity. Unfortunately, the transient responses of a quantum system to random changes in the amplitude, phase or polarization of a resonant field are not well understood, forming the basis of what has come to be known as the stochastic-field/atom interaction problem. As the first step in understanding the more complicated stochastic problem, the present work considers the response of a coherent-population-trapping (CPT) signal to a sudden, step-function change in laser polarization. We find that the transient behaviour depends on both the redistribution of atomic population among the atom's Zeeman sublevels and the regeneration of atomic coherence between these sublevels. Despite the complicated nature of the dynamics, we develop and experimentally validate a semi-empirical, reasonably intuitive model of the CPT transient and demonstrate that in the 'typical' CPT signal the polarization-induced transients are dominated by redistribution of atomic population among the Zeeman sublevels. Further, the amplitudes of the polarization-induced transients are relatively large and could potentially 'swamp' the CPT signals of interest for UAP.
5 citations
TL;DR: In this article, experimental observations of interference between an atomic spin coherence and an optical field in a gradient echo memory are presented. But the interference is mediated by a strong classical field that couples a weak probe field to the atomic coherence through a resonant Raman transition.
Abstract: We present experimental observations of interference between an atomic spin coherence and an optical field in a {\Lambda}-type gradient echo memory. The interference is mediated by a strong classical field that couples a weak probe field to the atomic coherence through a resonant Raman transition. Interference can be observed between a prepared spin coherence and another propagating optical field, or between multiple {\Lambda} transitions driving a single spin coherence. In principle, the interference in each scheme can yield a near unity visibility.
5 citations