Speckle-correlation imaging through a kaleidoscopic multimode fiber

TL;DR

This paper introduces a novel speckle-correlation imaging method through a square-core multimode fiber using a kaleidoscopic memory effect, enabling fluorescence imaging without prior fiber knowledge and promising for minimally-invasive endoscopy.

Contribution

It demonstrates a new approach leveraging a kaleidoscopic memory effect in multimode fibers for non-invasive fluorescence imaging without requiring detailed fiber calibration.

Findings

Successful experimental fluorescence imaging through a multimode fiber

Imaging achieved without prior knowledge of fiber properties

Potential for flexible minimally-invasive endoscopic applications

Abstract

Speckle-correlation imaging techniques are widely used for non-invasive imaging through complex scattering media. While light propagation through multimode fibers and scattering media share many analogies, reconstructing images through multimode fibers from speckle correlations remains an unsolved challenge. Here, we exploit a kaleidoscopic memory effect emerging in square-core multimode fibers and demonstrate fluorescence imaging with no prior knowledge on the fiber. Experimentally, our approach simply requires to translate random speckle patterns at the input of a square-core fiber and to measure the resulting fluorescence intensity with a bucket detector. The image of the fluorescent object is then reconstructed from the autocorrelation of the measured signal by solving an inverse problem. This strategy does not require the knowledge of the fragile deterministic relation between input and output fields, which makes it promising for the development of flexible minimally-invasive endoscopes.