A5071821689- Digital Holography and Microscopy
- Terahertz technology and applications
- Optical measurement and interference techniques
- Advanced X-ray Imaging Techniques
- Orbital Angular Momentum in Optics
- Russia and Soviet political economy
- Superconducting and THz Device Technology
- Advanced Optical Imaging Technologies
- Random lasers and scattering media
- Photonic and Optical Devices
- Spectroscopy and Laser Applications
- Adaptive optics and wavefront sensing
- Gyrotron and Vacuum Electronics Research
- Advanced Fluorescence Microscopy Techniques
- Laser-Matter Interactions and Applications
- Optical Coherence Tomography Applications
- Near-Field Optical Microscopy
- Image Processing Techniques and Applications
- Advanced Fiber Laser Technologies
- Photorefractive and Nonlinear Optics
- Soil and Environmental Studies
- Political Conflict and Governance
- Sociopolitical Dynamics in Russia
- Photodynamic Therapy Research Studies
- Optical Systems and Laser Technology
ITMO University
2015-2024
Harbin Engineering University
2023-2024
Technical University of Gabrovo
2023
Institute of Physico-Technical Problems of the North named VP Larionov
2023
Siberian Branch of the Russian Academy of Sciences
2023
Udmurt State University
2023
Cardiff University
2022
ORCID
2022
Volgograd State Agricultural University
2020-2022
Karelian Research Centre
2022
Terahertz pulse time-domain holography (THz PTDH) is the powerful technique for high-resolution amplitude and phase THz imaging that allows mapping spectroscopic information across imaged object. In this paper, we consider most sought after applications of provided by experimentally demonstrate ability method to reconstruct smooth stepped relief features an object transparent in region. Unlike distribution, which does not contain any significant case, distribution only reveals qualitatively,...
Contents1. Materials for dynamic holographic 3D display 2. Photopolymerizable nanocomposite materials applications 3. Photopolymers the recording of waveguides 4. Shrinkage in materials: photopolymers 5. Advances photorefractive and devices 6. Industrial-scale material mass production vHOEs 7. Non-imaging optics solar energy conversion 8. Data security data storage 9. Multimodal acquisition using digital holography 10.EUV SXR tomography with compact short wavelength sources 11.Holographic...
In this paper, we consider computational super-resolution inverse diffraction phase retrieval. The optical setup is lensless, with a spatial light modulator for aperture coding. paper focused on experimental tests of the sparse amplitude retrieval algorithm. We start from simulations and proceed to physical experiments. Both simulation experiments demonstrate good-quality imaging factor 4 serious advantage over diffraction-limited resolution as defined by Abbe’s criterion.
In this paper, we review the existing approaches for vortex and vector beam shaping generation in terahertz frequency range. The particular focus of is on possibility homogeneous topological charge formation ultra-wide spectral interval inherent to ultrashort pulses. We available materials components, analyse proposed potentially possible solutions broadband shaping, compare all developed approaches, put forward a unified concept constructing passive shapers such beams from component base.
Abstract Terahertz pulse time-domain holography is the ultimate technique allowing evaluating a propagation of broadband terahertz wavefronts and analyze their spatial, temporal spectral evolution. We have numerically analyzed pulsed Gauss-Bessel beam’s both spatio-temporal spatio-spectral evolution in non-paraxial approach. characterized two-dimensional beam behavior demonstrated all stages reshaping during propagation, including X-shape forming. The also illustrated by energy transfer...
For hundreds of years, dictators have ruled Russia. Do they still? In the late 1980s, Soviet President Mikhail Gorbachev launched a series political reforms that eventually allowed for competitive elections, emergence an independent press, formation parties, and sprouting civil society. After collapse Union in 1991, these proto-democratic institutions endured But did processes unleashed by continued under Russian Boris Yeltsin lead to liberal democracy Russia? If not, what kind regime take...
A method is proposed for accelerating measurements ghost imaging reconstruction of objects using spectral multiplexing speckle patterns formed by broadband terahertz (THz) radiation. The presented aims at the challenge a sufficiently large number measurements, and increases correlation between reference reconstructed images. It experimentally shown that unique individual frequencies can be THz radiation while propagating through random phase plate. numerical simulation these used to decrease...
The measurement of the spatial distribution nearly monocyclic terahertz (THz) fields by a raster scanning diaphragm is widely used approach in THz pulse time-domain holography (PTDH) applied imaging, optical component design, and wavefront sensing tasks. However, it historically plagued compromise between balance signal-to-noise ratio (SNR) resolution. To address this challenge keep both parameters at high level, we proposed to replace aperture with module containing conjugated lens. This...
By using polarization-resolved common-path diffraction phase microscope coupled with spin-to-orbit converter, we experimentally study two dimensional in-plane distributions of amplitude and light transmitted through a spherulite formed in frustrated cholesteric liquid crystal cell. These measured at different orientations the output linear polarizer (analyzer) are used to obtain orbital angular momentum (OAM) spectra characterizing OAM content beam. The experimental data found be good...
By using polarization-resolved common-path diffraction phase microscope coupled with spin-to-orbit converter, we experimentally study two dimensional in-plane distributions of amplitude and light transmitted through a spherulite formed in frustrated cholesteric liquid crystal cell. These measured at different orientations the output linear polarizer (analyzer) are used to obtain orbital angular momentum (OAM) spectra characterizing OAM content beam. The experimental data found be good...
An American political scientist and a Russian geographer, specialists in postCommunist reform regional politics, respectively, adopt subnational approach to democratization, measuring democracy standard fashion across 57 regions of Russia. They rate levels Russia's oblasts, krays, federal cities based on the results survey they administered experts provincial politics. The article presents ranking regions, evaluates as means democracy, examines five possible explanations for variation...
This paper presents experimental results and an analysis of methods generating terahertz (THz) radiation, using femtosecond laser sources: generation by photoconductive semiconductor antennas, nonlinear-optical the difference frequency or optical rectification, breakdown in gases under action pulses. An undoped crystal indium arsenide (InAs) located a magnetic field, electrooptic ZnTe crystal, organic DAST spark air were used as generators THz radiation
We present measurements of optical characteristics sodium polyacrylate in the terahertz frequency range and discuss how material dispersion affects object visualisation imaging. demonstrate important is to take into account for phase relief reconstruction investigated object.
In this paper, we present review and latest results obtained in the scope of terahertz holographic other methods for phase retrieval imaging. Not only accurate change amplitude, but also rigorous is essential precise calculation optical parameters samples range. Pulse holography introduced some years ago shows itself as perfect method overall-object technique, same time it allows measurement with low signal to noise that leads less derivation sample parameters. And certainly just...
A methodology providing noninvasive monitoring and evaluation of the effect photodynamic treatment on live cells in vitro is presented. Variations morphological characteristics course after are recorded by means digital holographic microscopy. High-precision measurements phase shift gained probe radiation HeLa human endometrial mesenchymal stem cell cultures demonstrate for first time changes their volume occurred response to treatment.
A comprehensive characterization of the diffraction properties terahertz (THz) pulsed broadband vortex beams consisting several electromagnetic field oscillations requires state-of-the-art techniques for studying evolution a wavefront as it propagates. For this purpose, we have applied capabilities offered by THz pulse time domain holography. Accurate metrological study single-period propagation allowed us to reveal spatio-temporal and spatiospectral couplings in uniformly topologically...
This work presents the new method for wavefront reconstruction from a digital hologram recorded in off-axis configuration. The main feature of proposed algorithm is good ability noise filtration due to original formulation problem taking into account presence intensity distribution and sparse phase amplitude approach with data-adaptive block-matching 3D technique. Basically, sparsity assumes that low dimensional models can be used approximations. dimensionality enables strong suppression...
Abstract In this paper, we present a novel numerical approach for increasing the resolution of retrieved images objects after their diffraction patterns are recorded via terahertz pulse time-domain holography (THz PTDH). THz PTDH allows spectrally resolved imaging with high spatial and does not require fine alignment complex optics in path. The proposed data post-processing method opens up possibility to reconstruct holograms spatially restricted detectors, overcome limit even...
The paper presents a novel algorithm based on digital holographic interferometry and being promising for evaluation of phase variations from highly noisy or modulated by speckle-structures holograms. suggested simulates an interferogram in finite width fringes, analogy with classical double exposure interferometry. Thus obtained is then processed as hologram. advantages the approach are demonstrated numerical experiments calculations differences distributions wave fronts speckle structure,...