Spatiotemporal focusing through a multimode fiber via time-domain wavefront shaping

TL;DR

This paper demonstrates a method to focus ultrashort pulses through a multimode fiber using time-domain wavefront shaping, enabling raster scanning and potential nonlinear imaging behind the fiber.

Contribution

It introduces a novel technique for spatiotemporal focusing of ultrashort pulses in multimode fibers via time-domain wavefront shaping, with experimental validation.

Findings

Successful raster scanning of ultrashort pulses through multimode fiber

Experimental results align with numerical simulations

Potential for nonlinear fluorescent imaging behind the fiber

Abstract

We shape fs optical pulses and deliver them in a single spatial mode to the input of a multimode fiber. The pulse is shaped in time such that at the output of the multimode fiber an ultrashort pulse appears at a predefined focus. Our result shows how to raster scan an ultrashort pulse at the output of a stiff piece of square-core step-index multimode fiber and in this way the potential for making a nonlinear fluorescent image of the scene behind the fiber, while the connection to the multimode fiber can be established via a thin and flexible single-mode fiber. The experimental results match our numerical simulation well.