Effect of anti-crossings with cladding resonances on ultrafast nonlinear dynamics in gas-filled PCFs

TL;DR

This paper investigates how anti-crossings with cladding resonances affect ultrafast nonlinear pulse dynamics in gas-filled photonic crystal fibers, revealing their role in spectral peak emission and how to mitigate their impact.

Contribution

It provides a detailed analysis of dispersion changes caused by anti-crossings and proposes a method to minimize their influence by adjusting core-wall thickness.

Findings

Anti-crossings induce narrow spectral peaks via four-wave mixing and dispersive waves.

Adjusting core-wall thickness can shift anti-crossings away from the pump wavelength.

Proper design reduces the impact of anti-crossings on nonlinear pulse propagation.

Abstract

Spectral anti-crossings between the fundamental guided mode and core wall resonances alter the dispersion in hollow-core anti-resonant-reflection photonic crystal fibers. Here we study the effect of this dispersion change on the nonlinear propagation and dynamics of ultrashort pulses. We find that it causes emission of narrow spectral peaks through a combination of four-wave mixing and dispersive wave emission. We further investigate the influence of the anti-crossings on nonlinear pulse propagation and show that their impact can be minimized by adjusting the core-wall thickness in such a way that the anti-crossings lie spectrally distant from the pump wavelength.