Enhanced opposite Imbert-Fedorov shifts of vortex beams for precise sensing of temperature and thickness

TL;DR

This paper demonstrates that vortex beams with large opposite orbital angular momentum significantly enhance the Imbert-Fedorov shift in resonant structures, enabling highly sensitive detection of temperature and thickness changes for advanced sensing applications.

Contribution

The study experimentally shows that large opposite OAM vortex beams amplify IF shifts in resonant structures, improving precision in sensing thickness and temperature.

Findings

Enhanced IF shifts with larger OAMs in resonant structures

High sensitivity to air gap thickness and temperature changes

Potential for precise environmental and structural sensing

Abstract

Imbert-Fedorov (IF) shift, which refers to a tiny transverse splitting induced by spin-orbit interaction at a reflection/refraction interface, is sensitive to the refractive index of a medium and momentum state of incident light. Most of studies have focused on the shift for an incident light beam with a spin angular momentum (SAM) i.e., circular polarization. Compared to SAM, orbital angular momentum (OAM) has infinite dimensions in theory as a new degree of freedom of light and plays an important role in light-matter coupling. We demonstrate experimentally that the relative IF shifts of vortex beams with large opposite OAMs are highly enhanced in resonant structures when light refracts through a double-prism structure (DPS), in which the thickness and temperature of the air gap are precisely sensed via the observed relative IF shifts. The thickness and temperature sensitivities increase as the absolute value of opposite OAMs increases. Our results offer a technological and practical platform for applications in sensing of thickness and temperature, ingredients of environment gas, spatial displacement, chemical substances and deformation structure.