Enhanced stability of the focus obtained by wavefront optimization in dynamical scattering media

TL;DR

This paper demonstrates that wavefront optimization can produce a focus with enhanced stability in dynamical scattering media, outperforming surrounding speckle stability, which is promising for deep in vivo imaging.

Contribution

It provides experimental evidence that wavefront shaping can achieve more stable focusing than speckle decorrelation in dynamic scattering environments.

Findings

Focus stability exceeds speckle decorrelation in certain conditions

Wavefront optimization extends focus lifetime in dynamic media

Heterogeneous stability of scattering sequences observed

Abstract

Focusing scattered light using wavefront shaping provides interesting perspectives to image deep in opaque samples, as e.g. in nonlinear fluorescence microscopy. Applying these technics to in vivo imaging remains challenging due to the short decorrelation time of the speckle in depth, as focusing and imaging has to be achieved within the order of the decorrelation time. In this paper, we experimentally study the focus lifetime after focusing through dynamical scattering media, when iterative wavefront optimization and speckle decorrelation occur over the same timescale. We show experimental situations with heterogeneous stability of the scattering sequences, where the focus presents significantly higher stability than the surrounding speckle.