The relationship between axial resolution and signal-to-noise ratio in optical coherence tomography

TL;DR

This paper reveals an inherent coupling between axial resolution and signal-to-noise ratio in optical coherence tomography for diffuse samples, impacting system design and imaging depth.

Contribution

It demonstrates the coupling between axial resolution and SNR in OCT for tissue-like samples, challenging the view of their independence.

Findings

Coupling exists in diffuse scattering samples, not mirror-like surfaces.

Adjusting resolution affects imaging depth and SNR.

Design considerations should account for this coupling.

Abstract

In optical coherence tomography (OCT), axial resolution and signal-to-noise ratio (SNR) are typically viewed as uncoupled parameters. We show that this is only true for mirror-like surfaces, and that in diffuse scattering samples such as tissue there is an inherent coupling between axial resolution and measurement SNR. We explain the origin of this coupling and demonstrate that it can be used to achieve increased imaging penetration depth at the expense of resolution. Finally, we argue that this coupling should be considered during OCT system design processes that seek to balance competing needs of resolution, sensitivity, and system/source complexity.