Circular polarization memory effect in low-coherence enhanced backscattering of light

Area of Science:

• Optics and photonics
• Condensed matter physics
• Wave propagation

Background:

• Enhanced backscattering (EBS), or coherent backscattering, is a wave phenomenon observed when light propagates through disordered media.
• Understanding light propagation in the subdiffusion regime is crucial for various applications, including imaging and material characterization.
• Circular polarization of light offers unique properties for probing complex scattering environments.

Purpose of the Study:

• To experimentally investigate the propagation of circularly polarized light in the subdiffusion regime using enhanced backscattering (EBS).
• To demonstrate the existence of a circular polarization memory effect in EBS for various scatterer sizes.
• To analyze the crossover of helicity-preserving and orthogonal helicity channels in low-coherence EBS signals.

Main Methods:

• Experimental study of light propagation using circularly polarized light.
• Exploitation of enhanced backscattering (EBS) under low spatial coherence illumination.
• Analysis of EBS signals across a range of scatterer sizes and varying mean free path lengths.

Main Results:

• Demonstration of a circular polarization memory effect in EBS for the first time.
• Observation of a crossover in low-coherence EBS signals between helicity-preserving and orthogonal helicity channels.
• Identification of the crossover point as an indicator for the transition from multiple to double scattering in EBS.

Conclusions:

• A circular polarization memory effect in EBS is confirmed over a wide range of scatterer sizes in the subdiffusion regime.
• The observed crossover in EBS signals provides a method to distinguish between multiple and double scattering events.
• This research advances the understanding of light-matter interactions in disordered media.