Controlling Enhancement of Transmitted Goos-H\"anchen Shifts: From Symmetric to Unidirectional

TL;DR

This paper presents a control framework for enhancing transmitted Goos-H"anchen shifts, enabling asymmetric and unidirectional shifts in transmission, with broad applications in sensing and optical switching.

Contribution

It introduces a novel control scheme that transitions from symmetric to unidirectional GH shifts in transmission, expanding the degrees of freedom for beam shift manipulation.

Findings

Achieved complete control from symmetric to unidirectional GH shifts.

Demonstrated broad application potential in sensing and optical devices.

Enhanced flexibility in beam shift control through new design framework.

Abstract

Since the discovery of the Goos-H\"anchen (GH) shift in the 1940s, its deep connections to Fourier transforms and causality have led to widespread interest and applications in optics, acoustics, and quantum mechanics. Control of the shift involves both its magnitude and direction. Although resonance-enhanced GH shift under reflection has significantly expanded and facilitated its observation and application, implementations in transmission scenarios remain scarce. More importantly, discussions on the direction of the GH shift are rare, and the associated degree of freedom for controlling directional asymmetry has not been fully explored. To address these issues, we discuss a control framework for enhancing transmitted GH shifts from symmetric to asymmetric. A design with complete degrees of freedom from symmetric shift enhancement to unidirectional shift enhancement is demonstrated in transmission scenarios. The control dimension associated with directionality significantly enhances the flexibility of beam shift control, with broad application prospects in scenarios such as high-sensitivity sensing, precision measurement, optical isolators, and asymmetric optical switches.