Sensorless wavefront correction in two-photon microscopy across different turbidity scales

TL;DR

This paper evaluates the performance of the DASH sensorless wavefront correction technique in two-photon microscopy across various turbidity levels, comparing it with a new version of CSA in simulations and experiments.

Contribution

It provides the first systematic analysis of DASH's effectiveness in mild to high turbidity conditions and introduces a modified CSA algorithm for improved correction.

Findings

DASH performs well across different turbidity levels in simulations and experiments.

The modified a-CSA algorithm shows improved convergence in mild turbidity.

Sensorless AO techniques can be optimized for various tissue scattering conditions.

Abstract

Adaptive optics (AO) is a powerful tool to increase the imaging depth of multiphoton scanning microscopes. For highly scattering tissues, sensorless wavefront correction techniques exhibit robust performance and present a straight-forward implementation of AO. However, for many applications such as live-tissue imaging, the speed of aberration correction remains a critical bottleneck. Dynamic Adaptive Scattering compensation Holography (DASH) -- a fast-converging sensorless AO technique introduced recently for scatter compensation in nonlinear scanning microscopy -- addresses this issue. DASH has been targeted at highly turbid media, but to-date it has remained an open question how it performs for mild turbidity, where limitations imposed by phase-only wavefront shaping are expected to impede its convergence. In this work, we study the performance of DASH across different turbidity regimes, in simulation as well as experiments. We further provide a direct comparison between DASH and a novel, modified version of the Continuous Sequential Algorithm (CSA) which we call Amplified CSA (a-CSA).