7 research outputs found
Optimizing OpenGL programs
У статті проаналізовано напрями оптимізації програм OpenGL через
використання атласів. Розглянуто роль взаємодії та рендерингу об’єктів.The article analyzes the directions for optimizing OpenGL programs through the use of atlases. The role of interaction and rendering of objects is considered
High-refractive index and mechanically cleavable non-van der Waals InGaS3
The growing families of two-dimensional crystals derived from naturally
occurring van der Waals materials offer an unprecedented platform to
investigate elusive physical phenomena and could be of use in a diverse range
of devices. Of particular interest are recently reported atomic sheets of
non-van der Waals materials, which could allow a better comprehension of the
nature of structural bonds and increase the functionality of prospective
heterostructures. Here, we study the optostructural properties of ultrathin
non-van der Waals InGaS3 sheets produced by standard mechanical cleavage. Our
ab initio calculation results suggest an emergence of authentically delicate
out-of-plane covalent bonds within its unit cell, and, as a consequence, an
artificial generation of layered structure within the material. Those yield to
singular layer isolation energies of around 50 meVA-2, which is comparable with
the conventional van der Waals material's monolayer isolation energies of 20 -
60 meVA-2. In addition, we provide a comprehensive analysis of the structural,
vibrational, and optical properties of the materials presenting that it is a
wide bandgap (2.73 eV) semiconductor with a high-refractive index (higher than
2.5) and negligible losses in the visible and infrared spectral ranges. It
makes it a perfect candidate for further establishment of visible-range
all-dielectric nanophotonics
Tailoring of the Distribution of SERS-Active Silver Nanoparticles by Post-Deposition Low-Energy Ion Beam Irradiation
The possibility of controlled scalable nanostructuring of surfaces by the formation of the plasmonic nanoparticles is very important for the development of sensors, solar cells, etc. In this work, the formation of the ensembles of silver nanoparticles on silicon and glass substrates by the magnetron deposition technique and the subsequent low-energy Ar+ ion irradiation was studied. The possibility of controlling the sizes, shapes and aerial density of the nanoparticles by the variation of the deposition and irradiation parameters was systematically investigated. Scanning electron microscopy studies of the samples deposited and irradiated in different conditions allowed for analysis of the morphological features of the nanoparticles and the distribution of their sizes and allowed for determination of the optimal parameters for the formation of the plasmonic-active structures. Additionally, the plasmonic properties of the resulting nanoparticles were characterized by means of linear spectroscopy and surface-enhanced Raman spectroscopy. Hereby, in this work, we demonstrate the possibility of the fabrication of silver nanoparticles with a widely varied range of average sizes and aerial density by means of a post-deposition ion irradiation technique to form nanostructured surfaces which can be applied in sensing technologies and surface-enhanced Raman spectroscopy (SERS)
Topological phase singularities in atomically thin high-refractive-index materials
Atomically thin transition metal dichalcogenides (TMDCs) present a promising
platform for numerous photonic applications due to excitonic spectral features,
possibility to tune their constants by external gating, doping, or light, and
mechanical stability. Utilization of such materials for sensing or optical
modulation purposes would require a clever optical design, as by itself the 2D
materials can offer only a small optical phase delay - consequence of the
atomic thickness. To address this issue, we combine films of 2D semiconductors
which exhibit excitonic lines with the Fabry-Perot resonators of the standard
commercial SiO/Si substrate, in order to realize topological phase
singularities in reflection. Around these singularities, reflection spectra
demonstrate rapid phase changes while the structure behaves as a perfect
absorber. Furthermore, we demonstrate that such topological phase singularities
are ubiquitous for the entire class of atomically thin TMDCs and other
high-refractive-index materials, making it a powerful tool for phase
engineering in flat optics. As a practical demonstration, we employ PdSe
topological phase singularities for a refractive index sensor and demonstrate
its superior phase sensitivity compared to typical surface plasmon resonance
sensors