3D time-domain beam mapping for studying nonlinear dynamics in multimode optical fibers

TL;DR

This paper introduces a novel space-time mapping technique that captures real-time, high-resolution spatiotemporal dynamics of nonlinear multimode optical fibers, enabling direct observation of intrapulse nonlinear mode interactions.

Contribution

The paper presents the first experimental method for direct, real-time observation of nonlinear mode coupling in multimode fibers using picosecond-resolved space-time mapping.

Findings

First direct observation of intrapulse nonlinear mode coupling

High temporal resolution imaging of beam evolution

Enhanced understanding of nonlinear dynamics in multimode fibers

Abstract

The characterization of the complex spatiotemporal dynamics of optical beam propagation in nonlinear multimode fibers requires the development of advanced measurement methods, capable of capturing the real-time evolution of beam images. We present a new space-time mapping technique, permitting the direct detection, with picosecond temporal resolution, of the intensity from repetitive laser pulses over a grid of spatial samples from a magnified image of the output beam. By using this time-resolved mapping, we provide the first unambiguous experimental observation of instantaneous intrapulse nonlinear coupling processes among the modes of a graded index fiber.