Chiral light-matter interactions in hot vapor cladded waveguides

TL;DR

This paper demonstrates the integration of alkali vapor with nanoscale waveguides to produce chiral light-matter interactions, enabling applications like optical isolation and magnetometry on a chip-scale platform.

Contribution

The authors designed and fabricated a miniaturized vapor cell integrated with waveguides that generate circular-like polarization, showing spectral shifts and wave isolation effects.

Findings

Spectral shift in atomic absorption with magnetic field variation

Significant forward-backward wave isolation in atomic-cladded waveguides

Potential for chip-scale optical isolation and high-resolution magnetometry

Abstract

Recently, there is growing interest in integrating alkali vapors with nanoscale photonic structures, such as nano-waveguides, resonators and nanoantennas. Nanoscale confinement of electromagnetic fields may introduce a longitudinal electric field component, giving rise to circularly polarized modes which are essential for diverse applications involving vapor and light, such as chirality and non-reciprocity. Hereby, we have designed, fabricated and characterized a miniaturized vapor cell that is integrated with optical waveguides that are designed to generate a peculiar circular-like polarization. Taking advantage of this phenomenon, we demonstrate a spectral shift in the atomic absorption signatures at varying magnetic fields, and significant isolation between forward and backward propagating waves in our atomic-cladded waveguide. Our results pave the way for the utilization of chip-scale integrated atomic devices in applications such as optical isolation and high spatial resolution magnetometry.