# Arago spot formation in the time domain

## TL;DR

This paper investigates the formation of the Arago spot in the time domain through theoretical analysis and experiments, revealing how nonlinearity and dispersion influence its emergence in optical fibers.

## Contribution

It introduces a novel study of Arago spot formation in the time domain, combining space-time duality, theory, and experimental validation in optical fibers.

## Key findings

- Arago spot forms in the time domain under linear propagation.
- Kerr nonlinearity and dispersion sign affect spot formation.
- Experimental confirmation using telecommunication fiber platform.

## Abstract

Using the space-time duality we theoretically and experimentally revisit the Arago spot formation in the time domain and explore the temporal emergence of a bright spot in the time shadow of an initial waveform. We describe the linear regime of propagation using Fresnel's integrals and show that in the presence of Kerr nonlinearity the Arago spot formation is affected depending on the sign of the dispersion. We finally confirm experimentally the Arago spot formation in the time domain using a telecommunication optical fiber platform.

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Source: https://tomesphere.com/paper/1902.06138