Germanium optical elements are widely used as passive components (lenses, prisms, windows, protective screens) of the great majority of infrared devices. During operation, especially under extreme conditions, such elements frequently suffer mechanical damage or lose transparency resulting from the degradation of anti-reflective coatings.
The report presents the results of...
Materials based on double molybdates have a promising application in the field of optoelectronic devices[1] due to their physical and chemical properties, and they also exhibit the phenomenon of upconversion, which is widely used in diagnostics, therapy, sensors, solar cells, photocalysis, bio-imaging[2].
The main goal is to obtain pure NaBi(MoO4)2 and NaBi0.5Eu0.5(MoO4)2 with tetragonal...
Among the promising and innovative technologies of today, nanoelectromechanical systems, nanoelectronics, and its subdivision - spintronics, occupy a leading place. At the same time, one-dimensional structures - nanocontacts and nanowires - are of particular interest, based on which it is possible to form highly efficient nanocircuits with small dimensions and low power consumption. However,...
Infrared absorption spectra of free molecules (CH3)2CO/HCl and (CH3)2COโขโขโขHCl complex are recorded in the 4000-400 cmโ1 region with a Bruker IFS-125 Fourier spectrometer in gas state and with Kr, Xe solutions at different temperatures. In the free acetone and its complex with HCl, the spectral characteristics of the fundamental ranges Q(C=O),
, Q-(C-C), and ฮฝHCl are measured. Particular...
Glasses based on borophosphate with the formula (45-0.5x)P2O5-xB2O3-10,0MoO3-(45-0.5x)Na2O where ๐ฅ = 20,0-60,0 have been manufactured using the melt-quenching methodology. Molybdenum oxide alone does not rank among glass-forming oxides, but it is able to enter the glass structure in the form of MoO4 tetrahedra or MoO6 octahedra with some glass-forming oxides, like P2O5. The regularities of...
Quantum chemical calculations of the structure and IR spectra of ibuprofen molecule were performed using various methods (HF, DFT, MP2). Several different conformers of ibuprofen were considered. The calculation results were compared with the experimentally registered spectra of ibuprofen. It is shown that MP2 method is the most appropriate for the description of the experimentally registered...
The analyzer-based imaging (ABI) is one of the most sensitive phase-contrast methods for weakly absorbing objects with low background due to high angular selectivity of analyzer crystal to scattered radiation. The most of the common approaches of ABI modelling are based on the approximation of geometrical optics for scattering in the non-crystalline sample and even in the analyzer crystal. At...
Optical properties of various transition-metal ions doped glasses have been under investigation in recent years in view of their technological applications, especially in lasers, phosphors, solar energy converters, plasma display panels and in a number of electronic devices. Molybdenum-containing glasses possess a variety of specific features, which arouse interest in view of their...
Microwave Kinetic Inductance Detectors (MKID) are widely used for detecting low-energy photons due to their high sensitivity and ease of multiplexing, with applications in astronomy and spectroscopy. This work investigates using Hilbert fractal planar resonators as a substitute for conventional straight or meander resonators in MKID. The study addresses challenges in miniaturizing resonators...
Multilayer ceramics have the potential to replace monolithic ceramics due to their improved mechanical properties, including increased hardness, durability, and fracture toughness. The diverse loading conditions faced by structural materials require the development of customized layered structures for specific applications. A key advantage of layered ceramic composites is their ability to...
Three-dimensional hybrid perovskites containing the aziridinium cation (AzrH)BX3 (where AzrH = aziridinium, B is Pb2+ or Sn2+ and X = Clโ, Brโ or Iโ) exhibit semiconductive properties, making them suitable candidates for photovoltaic applications. Small changes in the composition of perovskites are shown to have a defining impact on optoelectronic properties of the reported materials. This...
Zinc oxide (ZnO) is one of the best photoactive wide-gap metal-oxide semiconductor materials, whose optoelectronic properties are of great interest for nanophotonics [1,2]. In particular, photoexcited ZnO exhibits strong excitonic UV photoluminescence (PL) at room temperature (RT). But despite all advances in ZnO nanophysics, some features of RT excitonic PL of ZnO nanoparticles (NP) are not...
Theoretical modeling of electronic structures of heterostructure composites is a powerful tool for developing novel optical materials. This work presents the results of calculations of the excited electronic states and optical spectra of MoOโ groups and Bi ions, considered potential luminescence centers in the glass-ceramic composite "KBi(MoOโ)โ crystal@phosphate-molybdate glass of...
Infrared spectra (4000-400 cm-1) of free molecules CX3Y (X=H, D, Y=F, Cl, Br), HCl, and CX3YโขโขโขHCl mixtures in liquefied argon (90, 100-120 K) are recorded. The intermolecular interactions of the CX3YโขโขโขHCl complexes are studied using the DFT method based on the B3LYP/6โ311++G(d,p) basis set. The effect of deuterium (D), an isotope of the hydrogen atom (H), on the vibrational spectra of...
Polyvinylidene fluoride (PVDF) is an organic polymer that exhibits significant potential and commercial appeal for modern applications in nanotechnology, microelectronics, and biomedicine. A real PVDF polymer is almost always a mixture of several polymorphic phases that are difficult to separate. Determining the phase composition of PVDF mixtures is a critical technological task. This report...
Structures with GeSn films of different thicknesses CVD-grown on Ge/Si substrates were studied by temperature-dependent spectroscopy of impedance Z = Z1 + iZ2 within 1 - 1000 kHz. At lower temperatures, the films revealed insets of the photosensitivity characteristic for interband excitation of GeSn, Ge (direct bandgap) and Si. From the frequency dependencies of real Z1 and imaginary Z2 parts...
The development of photovoltaic technology addresses the challenges posed by the energy crisis. A current priority in this field is to reduce the cost of solar cell (SC) production while achieving properties not typically found in crystalline silicon photovoltaic converters. Consequently, significant attention has shifted toward thin-film, organic, perovskite, and quantum dot solar cells....
Nonlinear Spatial Frequency Chirping Of Quadruple Gaussian Laser Beams Interacting with Narrowband Gap Semiconductors: Effect of Self Focusing
Nishu Malik and Naveen Gupta
Lovely Professional University, Phagwara
naveens222@rediffmail.com
nishumalik1230@gmail.com
Abstract
This paper investigates the nonlinear spatial frequency chirping (NSFC) of quadruple Gaussian (QG) laser...
Recently, increasing attention has been tuned to luminescence behaviour related to structure specialty of phosphor materials because microstructure of host material decides the fluorescence properties [1]. Phosphate is a good type of candidate for its reasonably large band gap, high thermal and chemical stability. The basic building block of phosphates is the PO4 tetrahedron and EuOx, which is...
This paper investigates the Gouy phase shift of Bessel-Gauss laser beams propagating through a plasma medium characterized by an axial temperature gradient. The interplay between the Bessel-Gauss beam profile and the self-focusing effect induced by the plasma is examined. The analytical expression for the Gouy phase shift is derived, incorporating the influence of both the beam's spatial...
Bismuth โ containing oxide materials have been attraction much attention as phosphors for light emitting diodes and other devices. Among them these ones containing tungsten are rarely studied due to a low chemical activity of tungsten compounds and high velocity evaporation of WO3 under thermal treatment.
Currently, Bi2WO6 have been attracting significant attention as optical...
Beer is one of the most popular drinks in the world. It is produced both at large-scale factories and in small craft breweries. Both producers and distributors of beer require cost-effective and stable ways to control and verify the authenticity of the drink. Traditional methods of evaluating beer properties are often expensive and require significant resources [1]. Recently, the industry has...
We consider formation of EHL in a transition metal dichalcogenide monolayer in a stochastic approach. The theoretical foundations were formulated in [A.A. Chernyuk et al., Physics Letters A 384, 126185 (2020)] for studying exciton liquid formation in semi-conductor quantum wells. In this work, an exciton gas is created in dichalcogenide plane by pumping. The exciton flux through the island...
This study focuses on the synthesis of CdxTeyOz films using the SILAR (Successive Ionic Layer Adsorption and Reaction) method, a cost-effective chemical deposition technique that enables precise control of nanocomposite structures. By investigating two batches of films with varying treatment cycles (five and ten), the research highlights the relationship between synthesis conditions and the...
Homogeneous glasses and class-ceramics can be produced by molten glass and converting it into a fine-grained ceramic by an appropriate heat treatment. Generally, wide range of glass-ceramic properties can be modified in a predictable way by changing the composition with a suitable heat treatment. The final crystalline phases depend on the composition of the glass and the heating methods. Thus,...
This research aims to investigate noncovalent interactions in various thiophene-2-carboxylic acid (TCA) solutions through experiments and simulations. Raman and infrared (IR) spectroscopy were utilized to analyse the vibrational characteristics of TCA in various solvent solutions. Experimental data analyzed using computing approaches include highest occupied molecular orbital (HOMO) and lowest...
In many small molecules the direction of the chemical bond, defined as the direction of the greatest change in the moleculeโs energy, appears not to coincide with the segment connecting the nuclei in a molecule. This phenomenon, first described in [1], is referred to as chemical bond deviation and has been thoroughly examined using classical 3N matrix method, e.g. [2], and ab initio methods,...
Non-contact optical thermometry is based on temperature dependence of fluorescence intensity ratio (FIR) of two spectral lines. Recently, fluorescence of rear-earth ions incorporated in wide-gap materials has been widely used for accurate temperature sensing.
Eu-doped and Sm-doped AlN thin films prepared by radio frequency magnetron sputtering were studied in terms of their applicability as...
