Transactions in Optics and Photonics

Vortex Structures in Optical Fibers Under the Influence of Third-Order Dispersion and Self-Steepening Effect

Fri, 24 Jan 2025 00:00:00 +0800

The present paper for the first time it is investigated the generation and formation of amplitude-type vortices, propagating in single-mode optical fibers with step-index profile under the influences of third-order dispersion and selfsteepening effect or so called dispersion of nonlinearity of the medium. The main model includes the vector nonlinear amplitude equation, from which a system of two scalar partial differential equations is derived. They describe the evolution of the x and y components of the vector amplitude function of an optical pulse under the influences of these higher order nonlinear and dispersive phenomena. New exact analytical solutions of the resulting system of equations were obtained in the form of optical vortices. They have amplitude type singularity and they are observed as ring structures in the components of the laser pulses. Numerical simulations of the found solutions are performed. It is shown that the vortex parameter m is related to the number of these ring structures. Significant depolarization of the vector electric field in the spot of the laser radiation is registered.

Complexity in Nonlinear and Quantum Optics by Considering Kolmogorov Derivatives and Change Complexity Information Measures

Dragutin T. Mihailović — Fri, 17 Jan 2025 00:00:00 +0800

One of the most challenging tasks in studying phenomena in nonlinear and quantum optics is determining the contributions of the complexities of individual components to the complexity of the entire system (master complexity). To examine these contributions, we considered this issue using information measures: Kolmogorov derivatives based on Kolmogorov complexity (KC) [KC spectrum, KC plane], change complexity (CC), and Lyapunov exponent (λ). We applied these measures to daily time series measured from 2003 to 2005 in Novi Sad (Serbia) for ultraviolet (UV) radiation, which represents a physical complex system, and water vapor pressure as individual components of that system. Based on the measures applied to UV radiation, we determined: (i) the level of chaos and randomness of the measured time series; (ii) the coordinates of points in the KC plane where master and individual amplitudes interact; and (iii) the range of UV radiation amplitudes in which changes in the interaction between the master and individual amplitudes are most pronounced.