arXiv subjects

José R. Salgueiro

Publications and source records attributed to José R. Salgueiro.

8 recordsLinked to original sources

arXiv2026

Optical vortex bullets with large angular momenta

We investigate three-dimensional spatiotemporal optical vortex solitons (light bullets with a toroidal shape) carrying higher-order orbital angular momentum in Kerr media with anomalous group-velocity dispersion and a transversely localized Gaussian profile of the linear refractive index. Stationary vortex bullets with topological charges (winding numbers) $1\leq \ell \leq 4$ are obtained as numerical solutions of the three-dimensional nonlinear Schrödinger equation, and their existence, structure and stability are systematically analyzed. In terms of atomic Bose-Einstein condensates, these solutions represent matter-wave solitons with embedded vorticity. We examine the dependence of the solution families on the propagation constant, the depth and width of the guiding profile, and $\ell $. It is found that the increase of $\ell $ requires one to use a stronger or wider waveguiding potential to sustain localized states satisfying the Vakhitov-Kolokolov (VK) stability criterion. VK-complying and non-complying branches of vortex-soliton families are separated by a degenerate Townes branch. Direct simulations reveal that, although the guiding profile substantially suppresses the collapse and extends the propagation distance of vortex bullets, their robustness is ultimately limited by azimuthal instabilities, whose growth is enhanced for values of $\ell $. These results demonstrate that engineered refractive-index landscapes significantly enlarge the stability domain of spatiotemporal vortex bullets and provide guidelines for supporting optical bullets carrying large orbital angular momenta.

physics.optics↗

arXiv2026

Three-dimensional optical vortices in nonlinear Bessel waveguides

We explore the formation, stability, and propagation dynamics of light bullets carrying orbital angular momentum (vorticity) in Bessel-structured nonlinear graded-index waveguides. While these waves are prone to the collapse in uniform three-dimensional media, we demonstrate that their stabilization is provided by a squared-Bessel index profile in the plane orthogonal to the propagation direction, which may play the role of the waveguiding or antiwaveguiding potential. Different solution families are obtained, revealing a variety of power-vs.-propagation-constant diagrams, characterizing the coexistence of multiple families. We analyze the propagation dynamics in a wide experimentally accessible parameter range. Our results contribute to the understanding of nonlinear light localization in multidimensional settings and suggest new possibilities for using structured light in advanced photonic applications.

physics.optics↗

arXiv2026

Exceptional light propagation via generalized bulk-edge correspondence

In topological photonics, the bulk-edge correspondence is conventionally imported by direct analogy with electronic systems, overlooking the fundamentally distinct spacetime symmetries of Maxwell's and Schrödinger's equations. In this work, we challenge this prevailing paradigm by demonstrating that non-trivial bulk topology alone is insufficient to guarantee localized edge states in photonic platforms. Using a Su-Schrieffer-Heeger-inspired photonic crystal, we unveil a generalized bulk-edge correspondence intrinsically shaped by the relativistic nature of electromagnetic waves. This constraint imposes a strict frequency cutoff, a feature fundamentally absent in electronic topological insulators, which enables a new regime of frequency-controlled spatial localization near the cutoff. Furthermore, we demonstrate that this generalized correspondence is polarization-dependent: transverse electric (TE) and transverse magnetic (TM) edge modes exist in different parameter regimes and exhibit distinct dispersion relations, including distinct zero-dispersion points. Our framework redefines the theoretical boundaries of topological photonics, unlocking new opportunities for polarization-selective dispersion engineering and robust pulse propagation in topological photonic platforms.

physics.optics↗

arXiv2025

Guided vortex bullets

By means of the variational method and numerical simulations, we demonstrate the existence of stable 3D nonlinear modes, viz. vortex ``bullets'', in the form of pulsed beams carrying orbital angular momentum, that can self-trap in a 2D waveguiding structure. Despite the attractive self-interaction, which is necessary for producing the bullets (bright solitons), and which readily leads to the collapse in the 3D setting as well as to spontaneous splitting of vortex modes, we find a critical value of the trapping depth securing the stabilization of the vortex bullets. We identify experimental conditions for the creation of these topological modes in the context of coherent optical and matter waves. Collisions between the bullets moving in the unconfined direction are found to be elastic. These findings contribute to the understanding of self-trapping in nonlinear multidimensional systems and suggest new possibilities for the stabilization and control of 3D topological solitons.

physics.optics↗

arXiv2004

Controllable matter-wave switchers with vector Bose-Einstein solitons

We show the possibility of producing matter-wave switching devices by using Manakov interactions between matter wave solitons in two-species Bose-Einstein Condensates (BEC). Our results establish the experimental parameters for three interaction regimes in two-species BECs: symmetric and asymmetric splitting, down-switching and up-switching. We have studied the dependence upon the initial conditions and the kind of interaction between the two components of the BECs.

cond-mat.soft↗

arXiv2004

Incoherent vector vortex-mode solitons in self-focusing nonlinear media

We suggest a novel type of composite spatial optical soliton created by a coherent vortex beam guiding a partially incoherent light beam in a self-focusing nonlinear medium. We show that the incoherence of the guided mode may enhance, rather than suppress, the vortex azimuthal instability, and also demonstrate strong destabilization of dipole-mode solitons by partially incoherent light.

nlin.PS↗

arXiv2004

Waveguiding properties of optical vortex solitons

We study the properties of linear and nonlinear waveguides induced by optical vortex solitons in both self-defocusing and self-focusing nonlinear media, for the case of a saturable nonlinear response. We demonstrate that the vortex-induced waveguides can guide both fundamental and first-order guided modes which together with the vortex may form, for larger amplitudes of the guide modes, different types of composite vortex-mode vector solitons. In the case of the self-focusing saturable medium, we demonstrate that a large-amplitude guided mode can stabilize the ring-like vortex structure which usually decays due to azimuthal modulational instability.

nlin.PS↗

arXiv2003

Second-harmonic generation in vortex-induced waveguides

We study the second-harmonic generation and localization of light in a reconfigurable waveguide induced by an optical vortex soliton in a defocusing Kerr medium. We show that the vortex-induced waveguide greatly improves conversion efficiency from the fundamental to the second harmonic field.

nlin.PS↗