The optical theorem for the conservation of the electromagnetic helicity: Its significance for molecular transfer and enantiomeric discrimination by dichroism

TL;DR

This paper establishes an optical theorem for electromagnetic helicity conservation, highlighting its importance in molecular transfer and enantiomeric discrimination through dichroism, with implications for new detection methods.

Contribution

It introduces the optical theorem for helicity, analogous to energy conservation, and explores its implications for molecular interactions and circular dichroism detection.

Findings

Helicity conservation can be described by an optical theorem similar to energy.

The theorem has implications for helicity transfer between molecules.

New detection procedures for circular dichroism are proposed.

Abstract

We put forward the physical meaning of the conservation equation for the helicity on scattering of an electromagnetic field with a generally magnetodielectric bi-isotropic dipolar object. This is the optical theorem for the helicity that, as we find, plays a role for this quantity analogous to that of the optical thorem for energy. We discuss its consequences for helicity transfer between molecules and for new detection procedures of circular dichroism based on ellipsometric measurements.