Experimental study of z resolution in acousto-optical coherence tomography using random phase jumps on ultrasound and light

TL;DR

This paper experimentally investigates how the axial resolution in Acousto-Optical Coherence Tomography depends on phase jump timing and correlation length, comparing results with theoretical models and demonstrating image quality variations.

Contribution

It provides new experimental data on $z$ resolution dependence in AOCT and compares measurements with theoretical PSF, enhancing understanding of resolution control.

Findings

Resolution depends on phase jump timing and correlation length.

Experimental results align with theoretical PSF models.

Image quality varies with $z$ resolution parameters.

Abstract

Acousto-Optical Coherence Tomography (AOCT) is a variant of Acousto Optic Imaging (also called Ultrasound modulated Optical Tomography) that makes possible to get resolution along the ultrasound propagation axis $z$. We present here new AOCT experimental results, and we study how the $z$ resolution depends on time step between phase jumps $T_\phi$, or on the correlation length $\Delta z$. By working at low resolution, we perform a quantitative comparison of the $z$ measurements with the theoretical Point Spread Function (PSF). We present also images recorded with different $z$ resolution, and we qualitatively show how the image quality varies with $T_\phi$, or $\Delta z$.