Discrimination of Chiral and Helical Contributions to Raman Scattering of Liquid Crystals Using Vortex Beams

authored by

Silvia Müllner, Florian Büscher, Angela Möller, Peter Lemmens

Abstract

We use vortex photon fields with orbital and spin angular momentum to probe chiral fluctuations within liquid crystals. In the regime of iridescence with a well-defined pitch length of chirality, we find low energy Raman scattering that can be decomposed into helical and chiral components depending on the scattering vector and the topological charge of the incident photon field. Based on the observation of an anomalous dispersion we attribute quasielastic scattering to a transfer of angular momenta to rotonlike quasiparticles. The latter are due to a competition of short-range repulsive and long-range dipolar interactions. Our approach using a transfer of orbital angular momentum opens up an avenue for the advanced characterization of chiral and optically active devices and materials.

Type

Article

Journal

Physical review letters

Volume

129

ISSN

0031-9007

Publication date

10.11.2022

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Physics and Astronomy(all)

Electronic version(s)

https://doi.org/10.1103/PhysRevLett.129.207801 (Access: Unknown)
https://link.aps.org/doi/10.1103/PhysRevLett.129.207801 (Access: Unknown)