Vladlen G. Shvedov | Searcharxiv

arXiv2022

Formation and stability of vortex solitons in nematic liquid crystals

We study the propagation dynamics of bright optical vortex solitons in nematic liquid crystals with a nonlocal reorientational nonlinear response. We investigate the role of optical birefringence on the stability of these solitons. In agreement with recent experimental observations, we show that birefringence-induced astigmatism can eventually destabilize these vortex solitons. However, for low and moderate birefringence, vortex solitons can propagate stably over experimentally relevant distances.

physics.optics↗

arXiv2011

Can Quantum Mechanics explain the Evolution of the Universe?

This manuscript deals with a model of the evolution of an event space represented by the fundamental solution of a N-dimensional generalized Schrodinger equation for free matter. Specifically this solution can be applied to describe the 3D space evolution of the Universe in the forward direction in time. The model which is based on the presented solution is close to the well known Inflation theory, but is nonsingular, does not violate the conservation laws and is finite throughout the whole space at any moment of time. According to this model, the evolution progresses non-uniformly with a positive acceleration. Moreover, the model correctly approaches Hubble's law in the long-time limit. It is also shown that any source functions which describe substance and its physical fields set space topology of the Universe, but do not influence the general dynamics of its evolution.

physics.gen-ph↗

arXiv2010

Materials processing with tightly focused femtosecond vortex laser beams

This letter is the first demonstration of material modification using tightly focused femtosecond laser vortex beams. Double-charge femtosecond vortices were synthesized with the polarization-singularity beam converter described in Ref [1] and then focused using moderate and high numerical aperture optics (viz., NA = 0.45 and 0.9) to ablate fused silica and soda-lime glasses. By controlling the pulse energy we consistently machine high-quality micron-size ring-shaped structures with less than 100 nm uniform groove thickness.

physics.optics↗

arXiv2010

Materials processing with a tightly focused femtosecond vortex laser pulse

This letter is the first demonstration of material modification using tightly focused femtosecond laser vortex beams. Double-charge femtosecond vortices were synthesized with the polarization-singularity beam converter described in Ref [1] and then focused using moderate and high numerical aperture optics (viz., NA = 0.45 and 0.9) to ablate fused silica and soda-lime glasses. By controlling the pulse energy we consistently machine high-quality micron-size ring-shaped structures with less than 100 nm uniform groove thickness.

physics.optics↗

arXiv2010

Efficient Beam Converter for the Generation of Femtosecond Vortices

We describe an optical beam converter for an efficient transformation of Gaussian femtosecond laser beams to single- or double-charge vortex beams showing no spatial or topological charge dispersion. The device achieves a conversion efficiency of 75% for single- and 50% for double-charge vortex beams and can operate with high energy broad bandwidth pulses. We also show that the topological charge of a femtosecond vortex beam can be determined by analyzing its intensity distribution in the focal area of a cylindrical lens.

physics.optics↗

arXiv2009

Optical guiding of absorbing nanoclusters in air

We introduce a novel approach for all-optical trapping and manipulation of absorbing aerosol particles based on a photophoretic force. We demonstrate experimentally, in open air, the robust three-dimensional guiding of agglomerates of carbon nanoparticles with the size spanned for two orders of magnitude, from 100 nanometers to 10 microns, over the distances of a few millimeters, as well as their acceleration up to velocities of 1 cm/s and simultaneous trapping of a large number of particles.

physics.optics↗