Is multiplexed off-axis holography for quantitative phase imaging more spatial bandwidth-efficient than on-axis holography?

TL;DR

This paper compares on-axis and multiplexed off-axis holography in digital holographic microscopy, analyzing their spatial bandwidth efficiency and imaging performance to identify the most effective method.

Contribution

It introduces an efficiency score to evaluate and compare different holographic recording geometries, highlighting the advantages of multiplexed off-axis holography.

Findings

Multiplexed off-axis holography can be more spatial bandwidth-efficient.

Off-axis holography achieves comparable signal-to-noise ratio with optimized multiplexing.

The optimal holographic method depends on specific imaging requirements.

Abstract

Digital holographic microcopy is a thriving imaging modality that attracts considerable research interest due to its ability to not only create excellent label-free contrast, but also supply valuable physical information regarding the density and dimensions of the sample with nanometer-scale axial sensitivity. Three basic holographic recording geometries currently exist, including on-axis, off-axis and slightly off-axis holography, each of them enabling a variety of architectures in terms of bandwidth use and compression capacity. Specifically, off-axis holography and slightly off-axis holography allow spatial hologram multiplexing, enabling compressing more information into the same digital hologram. In this paper, we define an efficiency score used to analyze the various possible architectures, and compare the signal-to-noise ratio and mean squared error obtained using each of them, determining the optimal holographic method.