Resolution-enhanced OCT and expanded framework of information capacity and resolution in coherent imaging

TL;DR

This paper introduces a method to enhance transverse resolution in optical coherence tomography beyond traditional limits by leveraging information capacity principles and computational techniques, enabling better visualization without hardware modifications.

Contribution

The authors develop a resolution-enhanced OCT approach based on information capacity invariance, expanding the theoretical framework of coherent imaging and demonstrating practical resolution improvements.

Findings

Achieved 1.5x resolution enhancement in phantom imaging.

Improved visualization of microstructures in biological tissues.

Method is compatible with existing OCT systems without hardware changes.

Abstract

Spatial resolution in optical microscopy has traditionally been treated as a fixed parameter of the optical system. Here, we present an approach to enhance transverse resolution in beam-scanned optical coherence tomography (OCT) beyond its aberration-free resolution limit, without any modification to the optical system. Based on the theorem of invariance of information capacity, resolution-enhanced (RE)-OCT navigates the exchange of information between resolution and signal-to-noise ratio (SNR) by exploiting efficient noise suppression via coherent averaging and a simple computational bandwidth expansion procedure. We demonstrate a resolution enhancement of 1.5 times relative to the aberration-free limit while maintaining comparable SNR in silicone phantom. We show that RE-OCT can significantly enhance the visualization of fine microstructural features in collagen gel and ex vivo mouse brain. Beyond RE-OCT, our analysis in the spatial-frequency domain leads to an expanded framework of information capacity and resolution in coherent imaging that contributes new implications to the theory of coherent imaging. RE-OCT can be readily implemented on most OCT systems worldwide, immediately unlocking information that is beyond their current imaging capabilities, and so has the potential for widespread impact in the numerous areas in which OCT is utilized, including the basic sciences and translational medicine.