Scattering Activities Bounded by Reciprocity and Parity Conservation

TL;DR

This paper explores how reciprocity and parity conservation fundamentally bound scattering activities in achiral reciprocal systems, providing a universal framework to understand diverse chiroptical effects beyond specific models.

Contribution

It introduces a fundamental, model-independent analysis of scattering activities constrained by symmetry laws, unifying various chiroptical phenomena under a common theoretical framework.

Findings

Scattering activities are bounded by reciprocity and parity conservation.

Extinction activity is often eliminated by symmetry, but scattering activities can still occur.

The framework applies broadly, revealing hidden connections between chiroptical effects.

Abstract

Scattering activities are generally manifest through different optical responses of scattering bodies to circularly polarized light of opposite handedness. Similar to the ubiquitous roles played by scattering theory across different branches of photonics, scattering activities can serve as a fundamental concept to clarify underlying mechanisms of various chiroptical effects, both within and beyond scattering systems. In this work we investigate scattering activities for reciprocal systems that exhibit various geometric symmetries but are intrinsically achiral. We reveal how scattering activities are generally bounded by reciprocity and parity conservation, demonstrating that though extinction activity is usually eliminated by symmetry, scattering activities in forms of distinct absorptions, scatterings or angular scattering patterns can more widely emerge. Since our analyses are solely based on fundamental laws of reciprocity and parity conservation, regardless of geometric and optical parameters of the scattering systems studied, the principles revealed are generically applicable. The intuitive and pictorial framework we have established is beyond any specific coupling models, able to reveal hidden connections between seemingly unrelated chiral manifestations, and thus more accessible for a unified understanding of various chiroptical effects.