Anisotropy in Fourier space optical memory effect correlations

TL;DR

This paper explores how anisotropy affects Fourier-space speckle correlations in optical memory effects within disordered media, revealing the importance of axial wavevector differences.

Contribution

It introduces a theoretical framework showing axial wavevector differences influence correlation strength, supported by numerical simulations and analysis of pseudo-correlations.

Findings

Correlation strength depends on axial wavevector differences.

Numerical simulations agree with the theoretical predictions.

Axial disorder plays a significant role in scattered field correlations.

Abstract

We investigate anisotropy in Fourier-domain speckle correlations associated with the optical memory effect in disordered scattering media. Within a single scattering framework, we show that while the conventional memory effect constrains transverse wavevector shifts, the correlation strength also depends non-trivially on differences in the axial wavevector components. Our theory is supported by numerical simulations of a three-dimensional, single scattering medium, which show excellent agreement with theory. We extend the analysis to pseudo-correlations, demonstrating that analogous anisotropic behavior arises in the conjugate memory effect. Our results highlight the often neglected role of axial disorder in scattered field correlations.