arXiv:1303.1376 · Physical Review A

Control of beam propagation in optically written waveguides beyond the paraxial approximation

Lida Zhang, Tarak Nath Dey, Jörg Evers

Published Apr 30, 2013• 20 citations

Abstract

Beam propagation beyond the paraxial approximation is studied in an optically written waveguide structure. The waveguide structure, which leads to diffractionless light propagation, is imprinted on a medium consisting of a five-level atomic vapor driven by an incoherent pump and two coherent spatially dependent control and plane-wave fields. We first study beam propagation in a single optically written waveguide and find that the paraxial approximation does not provide an accurate description of the probe propagation. We then employ coherent control fields such that two parallel and one tilted Gaussian beams produce a branched waveguide structure. The tilted beam allows selective steering of the probe beam into different branches of the waveguide structure. The transmission of the probe beam for a particular branch can be improved by changing the width of the titled Gaussian control beam as well as the intensity of the spatially dependent incoherent pump field.

DOI: 10.1103/physreva.87.043842

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arXiv:1303.1376 · Physical Review A

Control of beam propagation in optically written waveguides beyond the paraxial approximation

Lida Zhang, Tarak Nath Dey, Jörg Evers

Published Apr 30, 2013• 20 citations

arXiv HTML PDF

Abstract

DOI: 10.1103/physreva.87.043842

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\Delta_P/\gamma

), Kerr, coherent pump, and control field characteristics such as Rabi frequencies and detunings (

\Omega_{1,2,3}/\gamma

\Delta_{1,2,3}/\gamma

), as well as spatial coordinates

x/\omega_0

and

y/\omega_0

, where

\omega_0

denotes the Gaussian beam waist. Through systematic analysis, we elucidate the intricate effects of these parameters on the modulation of the HG probe field within the atomic medium. The study not only contributes to the fundamental understanding of light-matter interactions in complex atomic systems but also holds promise for potential applications in quantum information processing and communication. The results provide valuable insights into the control and manipulation of light beams in spatially varying media, paving the way for advancements in quantum optics and atomic physics.

\Delta_P/\gamma

), Kerr, coherent pump, and control field characteristics such as Rabi frequencies and detunings (

\Omega_{1,2,3}/\gamma

\Delta_{1,2,3}/\gamma

), as well as spatial coordinates

x/\omega_0

and

y/\omega_0

, where

\omega_0

We propose an efficient scheme for the generation of tunable optical waveguides based on atomic vapor in an

N

-type configuration. We exploit both control-field-induced transparency and Kerr-field-induced absorption to produce a flexible probe transparency window otherwise not feasible. We employ a suitable spatial profile of control and Kerr beams to create a high contrast refractive index modulation that holds the key to guiding a weak narrow probe beam. Further, we numerically demonstrate that high-contrast tunable waveguide permits the propagation of different modes of probe beam to several Rayleigh lengths without diffraction. This efficient guiding of narrow optical beam may have important applications in large-density image processing and high-resolution imaging.