Scattering correlations of time-gated light

Mykola Kadobianskyi,Ioannis N. Papadopoulos,Benjamin Judkewitz,Thomas Chaigne,Roarke Horstmeyer

doi:10.1364/optica.5.000389

Abstract

Manipulating the propagation of light through scattering media remains a major challenge for many applications, including astronomy, biomedical imaging, and colloidal optics. Light can be focused through inhomogeneous media into any desired point with wavefront shaping techniques. However, scattering correlations, referred to as the optical memory effect, limit spatial range within the scattering medium, where a single wavefront correction remains accurate. Selecting only the weakly scattered light is a promising way to increase this correlation range. Here we investigate spatial scattering correlations by digitally time-gating the early arriving light in the spectral domain. We demonstrate that the range of the translational memory effect for the early arriving light is increased almost fourfold, paving the way for a range of scattering media imaging applications.

Highlights

IntroductionHigh resolution optical imaging of biological tissues is mostly limited to superficial layers
Due to scattering, high resolution optical imaging of biological tissues is mostly limited to superficial layers
The resolution of fluorescence imaging depends on the ability to form a sharp focus at a plane of interest, which becomes increasingly challenging for tissue layers thicker than a few scattering mean free paths (MFP)[1]

Summary

Introduction

High resolution optical imaging of biological tissues is mostly limited to superficial layers. With the advent of wavefront shaping, it became possible to control light propagation and focus both through[2,3] and inside[4,5,6] turbid media to a diffraction-limited spot, recently demonstrated through highly scattering samples that are almost 10 cm thick[7] This focus spot must be scanned around within the scatterer to form an image. Assuming the plane of interest is at a depth where excitation light arrives after multiple scattering events, different incident wavefronts are needed to focus the incident light into neighboring points This would require a new round of wavefront correction for every scanned point, making imaging practically impossible for most applications

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