The next dimension: Digital holography for 3D interferometric scattering

TL;DR

This paper details the implementation of digital holography for high-sensitivity interferometric scattering, providing experimental guidelines, data processing techniques, and demonstrating its broad applicability in nanosizing and particle characterization.

Contribution

It introduces a comprehensive approach to digital holography in iSCAT, including experimental setup, data processing, and 3D tracking, advancing nanoscale imaging capabilities.

Findings

Effective digital refocusing and 3D particle tracking demonstrated

Aberration correction improves image quality and accuracy

Broad applicability in nanosizing and particle characterization

Abstract

We provide detailed experimental guidelines for implementing digital holography in the context of high-sensitivity interferometric scattering (iSCAT) based nanosizing applications. Our approach relies on interferometry via the highly versatile off-axis implementation of digital holography, which offers key advantages over more traditional strategies. After a brief theoretical discussion of off-axis holography and its differences and similarities with iSCAT, typical experimental implementations and digital data-processing steps are presented. Key experimental parameters and strategies to achieve optimal performance are also highlighted. Following these experimental aspects, we focus on digital post-processing routines that enable digital refocussing and 3D particle tracking as well as pupil function aberration correction. We then conclude with a few examples highlighting the broad applicability of digital holography for nanosizing and particle characterisation applications as well as an outlook for future applications.