Coherent control of the Goos-H\"{a}nchen shift in Otto structure

TL;DR

This paper demonstrates how the lateral Goos-Hänchen shift can be precisely controlled in an Otto structure by using a four-level atomic medium, enabling switching from positive to negative shifts through external field adjustments.

Contribution

It introduces a method to control the GH shift in Otto structures using a coherently driven atomic medium, offering tunable optical properties without changing the structure's geometry.

Findings

The sign and magnitude of the GH shift can be highly controlled.

Switching between transparent and absorptive states is achievable via external fields.

The control does not require altering the physical structure.

Abstract

We investigate controlling the lateral Goos-H\"{a}nchen (GH) shift for a TM-polarized field reflected from Otto structure containing four level N-type atomic medium. The N-type atomic configuration can be formed by coupling the standard three-level $\Lambda$ system to an additional upper energy level through a coherent driving field. The medium can then be switched from transparent to absorptive under the effect of the driving field. In the Otto structure, an air gap typically separates a dielectric prism from a metal film. We show that the sign and magnitude of the GH shift can be highly controlled when the air gap is replaced by the coherent atomic medium. This can be achieved by adjusting the strength of the applied fields to the atomic medium, while the geometrical characteristics of the proposed structure are unchanged.