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arXiv · 2608.30732

Robust bistable vortex light bullets in graded-index multimode fibers

Ashis Paul·Anuj P. Lara·Govind P. Agrawal·Samudra Roy
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Abstract

We explore theoretically the formation and evolution of spatiotemporal vortex bullets, pulses confined in both space and time while carrying orbital angular momentum, inside a graded-index multimode fiber. Through a two-fold approach, combining variational analysis with full numerical simulations, we establish the existence of a bistable vortex soliton family, characterized by distinct radial and azimuthal quantum numbers. These wave packets exhibit a Laguerre-Gaussian multi-ring topology in their spatiotemporal structure. We identify the experimental conditions necessary for the generation of such structured states of light. A stability analysis based on Vakhitov-Kolokolov criteria reveals an upper limit for the propagation constant, below which vortex bullets are found to be stable. Stationary and non-stationary dynamics of vortex bullets with different topological charges are analyzed fully, exploiting analytical techniques that are supported by full numerical simulations. These results enhance our understanding of self-trapped, spatiotemporal vortex solitons in a graded-index medium and may lead to potential applications in the area of classical and quantum information processing.

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Ashis Paul, Anuj P. Lara, Govind P. Agrawal, Samudra Roy. 2026-08-31. Robust bistable vortex light bullets in graded-index multimode fibers. https://arxiv.org/abs/2608.30732

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