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Circular Dichroism without Absorption in Isolated Chiral Dielectric Mie Particles.
Rafael S Dutra1, Felipe A Pinheiro2, Diney S Ether2
1LISComp-IFRJ, Instituto Federal de Educação, Ciência e Tecnologia, Rua Sebastião de Lacerda, Paracambi 26600-000, Brasil.
ACS Photonics
|February 23, 2026
Summary
Chiral dielectric microspheres can exhibit circular dichroism, a novel chiroptical effect. This phenomenon, observed in the Mie regime, shows scattered light becoming circularly polarized, aiding in single microparticle characterization.
Area of Science:
- Optics and Photonics
- Materials Science
- Physical Chemistry
Background:
- Chiroptical effects like circular dichroism are typically associated with molecular chirality.
- Dielectric and isotropic spherical particles have not been previously recognized for exhibiting such effects.
Purpose of the Study:
- To investigate the possibility of a circular dichroism-like phenomenon in chiral dielectric microspheres.
- To analyze the polarimetry of light scattered from these particles.
Main Methods:
- Theoretical analysis of light scattering from a chiral, lossless microsphere.
- Examination of polarimetric properties, specifically the Stokes parameter S3.
- Consideration of the Mie scattering regime and high numerical aperture (NA) light collection.
Main Results:
- Demonstration of a phenomenologically analogous circular dichroism effect in dielectric chiral microspheres.
- Observation of nearly circularly polarized scattered light with large nonresonant Stokes parameter S3 values.
- The effect is dependent on the microsphere radius being comparable to the wavelength and collection by a high-NA objective.
Conclusions:
- A novel chiroptical effect can be observed in isolated dielectric chiral particles.
- This finding provides a theoretical basis for experimental verification.
- Potential applications include enantioselection and characterization of individual microparticles based on their chiral response.
Keywords:
chiralitycircular dichroismdielectric nanoparticlesmie scatteringnonparaxial opticspolarimetryMore Related Videos
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