Speckle-based 3D sub-diffraction imaging through a multimode fiber

TL;DR

This paper introduces a novel method for fast 3D super-resolution imaging through multimode fibers, enabling depth-resolved visualization with sub-diffraction resolution using a single 2D scan.

Contribution

It presents a new approach combining speckle illumination and bucket detection for 3D imaging through multimode fibers, surpassing previous 2D limitations.

Findings

Achieved 3x smaller FWHM than diffraction limit along axial direction

Demonstrated precise 3D imaging of scattering samples

Enabled depth-resolving capacity for fiber endoscopes

Abstract

A flexible multimode fiber is an exceptionally efficient tool for in vivo deep tissue imaging. Recent advances in compressive multimode fiber sensing allow for imaging with sub-diffraction spatial resolution and sub-Nyquist speed. At present, the technology is limited to imaging in a two-dimensional (2D) plane near the fiber distal facet while in real applications it is very important to visualize three-dimensional (3D) structures. Here we propose a new approach for fast sub-diffraction 3D imaging through a multimode fiber by using a single 2D scan, speckle illumination, and bucket detection. We experimentally demonstrate precise image plane location as well as 3D imaging of samples with various scattering coefficients. The full width at half maximum (FWHM) of the point spread function along the axial direction is 3 times smaller than the diffraction limit. Our study grants depth-resolving capacity to ultra-thin super-resolution fiber endoscopes for life science and medical applications.