Influence of the absorber dimensions on wavefront shaping based on volumetric optoacoustic feedback

TL;DR

This paper investigates how the size of absorbing microparticles affects wavefront shaping using volumetric optoacoustic feedback, with implications for focusing light deep within scattering media.

Contribution

It experimentally demonstrates the influence of absorber dimensions on light enhancement in optoacoustic feedback-based wavefront shaping.

Findings

Larger absorbers improve light intensity enhancement.

Optimal absorber size depends on speckle resolution.

Results inform focusing strategies in scattering media.

Abstract

The recently demonstrated control over light distribution through turbid media based on real-time three-dimensional optoacoustic feedback has offered promising prospects to interferometrically focus light within scattering objects. Nevertheless, the focusing capacity of the feedback-based approach is strongly conditioned by the number of effectively resolvable optical modes (speckles). In this letter, we experimentally tested the light intensity enhancement achieved with optoacoustic feedback measurements from different sizes of absorbing microparticles. The importance of the obtained results is discussed in the context of potential signal enhancement at deep locations within a scattering medium where the effective speckle sizes approach the minimum values dictated by optical diffraction.