# Circular Dichroism without Absorption in Isolated Chiral Dielectric Mie Particles

## TL;DR

This paper shows that chiral dielectric particles can produce circularly polarized light without absorption, offering new ways to study chiral effects at the microscale.

## Contribution

The novel contribution is demonstrating a chiroptical effect in dielectric Mie particles that mimics circular dichroism without absorption.

## Key findings

- Scattered light from chiral microspheres becomes nearly circularly polarized.
- Large nonresonant Stokes parameter S3 values are observed across visible frequencies.
- The effect occurs in the Mie regime with high-NA objective lenses capturing nonparaxial components.

## Abstract

We demonstrate that an effect phenomenologically analogous
to circular
dichroism can arise even for dielectric and isotropic chiral spherical
particles. By analyzing the polarimetry of light scattered from a
chiral, lossless microsphere illuminated with linearly polarized light,
we show that the scattered light becomes nearly circularly polarized,
exhibiting large nonresonant values of the Stokes parameter S
3 for a broad range of visible frequencies.
This phenomenon occurs only in the Mie regime, with the microsphere
radius comparable to the wavelength, and provided that the scattered
light is collected by a high-NA objective lens, including nonparaxial
Fourier components. Altogether, our findings offer a theoretical framework
and motivation for an experimental demonstration of a novel chiroptical
effect with isolated dielectric particles, with potential applications
in enantioselection and characterization of single microparticles,
each and every one with its own chiral response.