Systematic control of Raman scattering with topologically induced chirality of light

TL;DR

This paper demonstrates that by controlling the topological charge of light, one can fundamentally alter the spectral shape and strength of Raman scattering, offering a new method to modulate this ubiquitous nonlinear process.

Contribution

It introduces a novel approach to control Raman scattering using topologically induced light chirality via spin-orbit interactions.

Findings

Spectral shape of Raman scattering can be altered by over half the Raman shift.

Raman scattering strength can be increased by about 100 times.

Control of topological charge enables modulation of Raman signals.

Abstract

Stokes Raman scattering is known to be a particularly robust nonlinearity, occurring in virtually every material, with spectra defined by the material and strengths dependent on the material as well as light intensities. This ubiquity has made it an indispensable tool in spectroscopy, but also presents itself as a stubborn source of noise or parasitic emission in several applications. Here, we show that orbital angular momentum carrying light beams experiencing spin-orbit interactions can fundamentally alter the selection rules for Raman scattering. This enables tailoring its spectral shape (by over half the Raman shift in a given material) as well as strength (by about 100 times) simply by controlling the topological charge of light, which is a capability of utility across the multitude of applications where modulating Raman scattering is desired.