Fiber Endoscopy Using Synthetic Wavelengths for 3D tissue imaging

TL;DR

This paper introduces a novel fiber endoscopy technique combining Synthetic Wavelength Imaging with fiber optics, enabling 3D imaging of tissue behind scattering layers without lenses or precise fiber positioning.

Contribution

The work presents a new method integrating SWI with fiber endoscopy to achieve lensless, robust 3D imaging through scattering layers, overcoming phase scrambling and alignment issues.

Findings

Successfully imaged 750-micrometer features behind scattering layers

Eliminated need for lenses in fiber endoscopy

Enhanced robustness against phase scrambling and fiber bending

Abstract

Fiber-based endoscopes utilizing multi-core fiber (MCF) bundles offer the capability to image deep within the human body, making them well-suited for imaging applications in minimally invasive surgery or diagnosis. However, the optical fields relayed through each fiber core can be significantly affected by phase scrambling from height irregularities at the fiber ends or potential multi-mode cores. Moreover, obtaining high-quality endoscopic images commonly requires the fiber tip to be placed close to the target or relies on the addition of a lens. Additionally, imaging through scattering layers after the fiber tip is commonly not possible. In this work, we address these challenges by integrating Synthetic Wavelength Imaging (SWI) with fiber endoscopy. This novel approach enables the endoscopic acquisition of holographic information from objects obscured by scattering layers. The resulting endoscopic system eliminates the need for lenses and is inherently robust against phase scrambling caused by scattering and fiber bending. Using this technique, we successfully demonstrate the endoscopic imaging of features approximately 750micrometers in size on an object positioned behind a scattering layer. This advancement represents significant potential for enabling spatially resolved three-dimensional imaging of objects concealed beneath tissue using fiber endoscopes, expanding the capabilities of these systems for medical applications.