Optical Coherence Tomography in Soft Matter

TL;DR

This review introduces Optical Coherence Tomography (OCT) as a versatile, high-resolution, non-invasive imaging technique for studying complex soft matter and fluid systems, providing practical guidance and case studies.

Contribution

It offers a comprehensive introduction, tutorials, and practical guidelines for adopting OCT in soft matter research, highlighting its versatility through diverse case studies.

Findings

OCT enables high-resolution, non-invasive measurements in soft matter.

Case studies demonstrate OCT's application in velocimetry and fluid-structure analysis.

Practical guidelines help researchers avoid common pitfalls.

Abstract

Optical Coherence Tomography (OCT) has become an indispensable tool for investigating mesoscopic features in soft matter and fluid mechanics. Its ability to provide high-resolution, non-invasive measurements in both spatial and temporal domains bridges critical gaps in experimental instrumentation, enabling the study of complex, confined, and dynamic systems. This review serves as both an introduction to OCT and a practical guide for researchers seeking to adopt this technology. A set of tutorials, complemented by Python scripts, are provided for both intensity- and Doppler-based techniques. The versatility of OCT is illustrated through case studies, including time-resolved velocimetry, particle-based velocity measurements, slip velocity characterization, detection of shear-induced structures, and analysis of fluid-fluid and fluid-structure interactions. Drawing on our experiences, we also present a set of practical guidelines for avoiding common pitfalls.