[institut] Reminder - Photonics Center Seminar, Monday, 16. 03. 2026. at 12h

[Mihailo Rabasovic]

Dear colleagues,


You are kindly invited to the Photonics Center seminar, which will be 
held on Monday, 16. 03. 2026. at 12h, in the "Dragan Popović" hall. The 
Laboratory of Theoretical Optics will be presented at the seminar. Dušan 
Arsenović will tell us something about the lab, and Jadranka Vasiljević 
will give a seminar entitled:

Shaping and controlling light curvature using structured light

The seminar abstract is below in the e-mail.


Best regards,
Mihailo Rabasović



Abstract:
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).

-- 
Institute of Physics
Pregrevica 118, 11080 Belgrade - Zemun, Serbia
phone: +381-11-3713-171
fax:   +381-11-3162-190
http://www.ipb.ac.rs/