On the Generation of Topological Vector Solitons from Bessel Like Beams

TL;DR

This paper reports the discovery of topologically knotted vector solitons generated from Bessel-like beams in nonlinear optics, demonstrating their invariant spatial profiles and complex collision behaviors.

Contribution

It introduces a novel method to generate linked, knotted vector solitons with topological features from Bessel-like beams in a nonlinear medium.

Findings

Generated topologically knotted vector solitons with invariant profiles

Observed soliton collision and rebound behavior at 90° angles

Demonstrated dependence of soliton geometry on topological charge

Abstract

Coupled solitary waves in optics literature, are coined vector solitons to reflect their particle--like nature that remains intact even after mutual collisions. They are born from a nonlinear change in the refractive index of an optical material induced by the light intensity. We've discovered that the second harmonic intensity profile generated by Bessel like beams, is composed of solitons of various geometries surrounded by concentric rings; one of which is two central solitons of similar radius knotted by ellipsoidal concentric rings. We observe that their geometry and intensity distribution is dependent on the topological charge of the fundamental Bessel beams incident on the nonlinear medium. We show that their spatial profile is invariant against propagation. We observe that their behavior is similar to that of screw dislocations in wave trains: they collide and rebound at a $90^\circ$ angle from the beam propagation direction. In this way, we have generated linked frequency doubled Bessel-type vector solitons with a with different topologies, that are knotted as they oscillate along the optical axis, when propagating in the laboratory environment.