# Hybrid photoacoustic/fluorescence microendoscopy through a multimode fiber using speckle illumination

## TL;DR

This paper introduces a compact hybrid imaging system combining photoacoustic and fluorescence microscopy through a multimode fiber, utilizing speckle illumination and a reconstruction algorithm for high-resolution imaging at the fiber tip.

## Contribution

It demonstrates a novel ultra-thin hybrid microendoscope integrating photoacoustic and fluorescence imaging using speckle illumination controlled by a digital micromirror device.

## Key findings

- Achieved optical resolution determined by the fiber's numerical aperture.
- Successfully performed imaging of samples at the fiber tip.
- Demonstrated the system's potential for minimally invasive biomedical imaging.

## Abstract

We present an ultra-thin hybrid imaging system based on an optical multimode fiber (MMF) and an optical fiber hydrophone that combines optical resolution photoacoustic and fluorescence microscopy. To control the illumination at the distal tip of the MMF, a digital micromirror device modulates the amplitude of the optical wavefront which is coupled into the MMF. A set of pre-calibrated speckle illuminations combined with a reconstruction algorithm enables photoacoustic and fluorescence imaging of samples located at the distal tip of the fiber with optical resolution determined by the numerical aperture.