Photochemical reaction enabling the engineering of photonic spin-orbit coupling in organic-crystal optical microcavities

TL;DR

This paper demonstrates a method to reversibly control photonic spin-orbit coupling in organic microcavities using photochemical reactions, enabling active manipulation of polarization states for advanced photonic device applications.

Contribution

It introduces a novel approach to dynamically engineer and switch photonic spin-orbit coupling via in situ photochemical reactions in organic microcavities.

Findings

Reversible control of spin-splitting in optical modes.

Observation of momentum-space polarization splitting.

Optical switching between polarization states.

Abstract

The control and active manipulation of spin-orbit coupling (SOC) in photonic systems is fundamental in the development of modern spin optics and topological photonic devices. Here, we demonstrate the control of an artificial Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a microcavity filled with an organic single-crystal of photochromic phase-change character. Splitting of the circular polarization components of the optical modes induced by photonic RD SOC is observed experimentally in momentum space. By applying an ultraviolet light beam, we control the spatial molecular orientation through a photochemical reaction and with that we control the energies of the photonic modes. This way we realize a reversible conversion of spin-splitting of the optical modes with different energies, leading to an optically controlled switching between circularly and linearly polarized emission from our device. Our strategy of in situ and reversible engineering of SOC induced by a light field provides a promising approach to actively design and manipulate synthetic gauge fields towards future on-chip integration in photonics and topological photonic devices.