У оквиру семинара Центра за фотонику Института за физику у Београду, у понедељак, 16. марта 2026. године у 12 часова у читаоници библиотеке „Др Драган Поповић“, др Јадранка Васиљевић (Институт за физику у Београду) одржаће предавање:
Shaping and controlling light curvature using structured light
САЖЕТАК:
Engineering and precise control of light curvature using structured nondiffracting beams is a topic of great research interest in nonlinear optics. Using a single-pass optical induction technique in photorefractive crystals (Strontium Barium Niobate), we are able to induce aperiodic photonic structures using nondiffracting beams. Nonlinear propagation of Weber beams leads to the emergence of parabolic
surface states and oscillatory discrete surface modes. In certain nonlinear regimes, Weber or modulated Bessel beams produce tilted discrete solitons under head-on incidence and without a pre-inscribed
lattice. Such a system exhibits high tunability: by adjusting various parameters of nondifracting beam, like beam order, scale, parabolicity, phase, modulation parameters, orientation due to the crystal optical
axis, and input power, we achieve precise control over soliton number, angle of tilted solitons, and surface geometry. We show that localized symmetry deviations combined with nonlinearity provide the fundamental mechanism for the excitation of tilted and surface modes, while effective guiding potentials arise dynamically during nonlinear evolution. Furthermore, we realize light-induced microstructures in the
form of twisted beam bundles distributed over curved geometries using modulated Bessel beams. Discrete solitons are observed to follow hyperboloidal trajectories, simultaniouslly inner beam components trace cylindrical paths, forming helicoidal waveguides and enabling transitions between multiple curved surfaces. These studies demonstrate that structured light in nonlinear media is a versatile platform for shaping beam trajectories, controlling discrete diffraction, and engineering complex curved photonic landscapes in aperiodic systems without a prefabricated lattice or tilted probe beam.
References:
1. Jadranka M. Vasiljević, Miroslav Petroski, Dejan V. Timotijević, Dragana M. Jović Savić, “Surface-Distributed twisted beams nonlinearly induced by nondiffracting beams”, ACS Applied Optical Materials (2026) – accepted for publication.
2. Dejan V. Timotijević, Aleksandra Ž. Piper, Jadranka M. Vasiljević, Damir V. Mitić, and Dragana M. Jović Savić, “Head-on nonlinear excitation of tilted linear modes in photorefractive medium”, Chaos, Solitons & Fractals 207, 117942 (2026).
3. Miroslav M. Petroski, Dejan V. Timotijević, Dragana M. Jović Savić, and Jadranka M. Vasiljević, “Head-on excitation of tilted solitons by fragmented Bessel beams”, Chaos, Solitons & Fractals 202(1), 117434, (2026).
4. Damir V. Mitić, Jadranka M. Vasiljević, Dejan V. Timotijević, Dragana M. Jović Savić, “Self-induced parabolic surface states“, Optical Materials 167, 117249 (2025).