arXiv subjects
Publications and source records attributed to Vladimir Osipov.
We have demonstrated that compact deformation sensors with heights and widths of about 100 micrometers can be fabricated by two-photon polymerization, using commercially available optical ferrules with embedded 125 micrometers-diameter optical fibers as the basic platform and the commercial photopolymers OrmoComp and FemtoBond as the fabrication materials.
We report on a novel dual-structure scaffold fabricated using two-photon polymerisation (2PP), integrating electrically conductive and non-conductive regions within a single architecture, targeting neural tissue regeneration. Poly(ethylene glycol) diacrylate (PEGDA) was combined with 20 nm gold nanoparticles to create a conductive microstructure, encapsulated within a biocompatible PEGDA lattice designed to support neuronal growth possibility after neural injuries. Electrical resistance measurements confirmed the feasibility of integrating conductive pathways into precision-fabricated microarchitectures.
We show that with the use of a short wavelength (520nm) femtosecond laser source, Two-Photon Polymerization (2PP) fabrication of micro-membrane designs with channel sizes down to 1 μm is possible, using commercial photopolymers OrmoComp and FemtoBond. This approach, involving the flexible design and direct manufacturing of micro-filters and micro-membranes, can be applied for novel microfluidic devices.
Relying on the local orientation of nanostructures, Pancharatnam-Berry metasurfaces are currently enabling a new generation of polarization-sensitive optical devices. A systematical mesoscopic description of topological metasurfaces is developed, providing a deeper understanding of the physical mechanisms leading to the polarization-dependent breaking of translational symmetry in contrast with propagation phase effects. These theoretical results, along with interferometric experiments, contribute to the development of a solid theoretical framework for arbitrary polarization-dependent metasurfaces.
We propose a method for designing multifocal diffractive lenses generating prescribed sets of foci with fixed positions at several different wavelengths. The method is based on minimizing the difference between the complex amplitudes of the beams generated by the lens microrelief at the design wavelengths, and the functions of complex transmission of multifocal lenses calculated for these wavelengths. As an example, a zone plate generating three fixed foci at three different wavelengths was designed, fabricated and experimentally investigated. The proof-of-concept experimental results confirm the formation of foci with fixed positions at the design wavelengths. The obtained results may find applications in the design and fabrication of novel multifocal contact and intraocular lenses with reduced chromatic effects.
In the framework of semiclassical theory the universal properties of quantum systems with classically chaotic dynamics can be accounted for through correlations between partner periodic orbits with small action differences. So far, however, the scope of this approach has been mainly limited to systems of a few particles with low-dimensional phase spaces. In the present work we consider N-particle chaotic systems with local homogeneous interactions, where N is not necessarily small. Based on a model of coupled cat maps we demonstrate emergence of a new mechanism for correlation between periodic orbit actions. In particular, we show the existence of partner orbits which are specific to many-particle systems. For a sufficiently large N these new partners dominate the spectrum of correlating periodic orbits and seem to be necessary for construction of a consistent many-particle semiclassical theory.