We propose an approach for fabricating one-dimensional magnetophotonic crystal microslabs (1D MCMS) that can be of used for concepts of spatial light modulators and integrated photonic circuits. The idea is to realize garnet crystallization by a laser and build in bismuth-substituted yttrium iron garnet elements into a functional microstructure. A series of the Fabry-Perot type 1D MCMS have been fabricated at different crystallization conditions. Structural, optical, and magneto-optical properties of the 1D MCMS have been studied in detail, illustrating an enhancement of the Faraday rotation (FR) by an order of magnitude. (c) 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

The work is devoted to structural study of Na+-Ag+ ion-exchanged photo-thermo-refractive (PTR) glass matrix by FTIR and Raman spectroscopies. FTIR reflectance spectra showed minor shift of the bands related to change in Si-O force constant in structural units associated with Na+ and Ag+ ions. On the other hand, Raman spectra showed progressive changes from glass surface deeper into bulk in bands related to 3-membered rings, mixed stretching-bending vibrations of Si-O-Si, and Si-O stretching vibrations in SiO4 tetrahedra with different amount of bridging/non-bridging oxygen atoms. Location and relative intensity of the indicated bands is shown to well correlate with the refractive index profile. The latter allows one to reconstruct concentration profile of silver ions in Na+-Ag+ ion-exchanged PTR glass matrix with high accuracy by Raman spectroscopy as a non-contact and non-destructive method.

In this work we successfully synthesize CsPb(BrxI1-x)3 perovskite nanocrystals with different Br/I ratio in a borogermanate glass matrix. The XRD studies show cubic perovskite phase peaks shift as the Br/I ratio changes. The formed nanocrystals have mean size of about 17 nm based on the calculations from the absorption spectra. The smooth change of the Br/I ratio in perovskite nanocrystals allow to obtain luminescence in the range 500 – 750 nm with quantum yield up to 35 %. The luminescence quantum yield and lifetime of the mixed-halide nanocrystals steadily increase with iodine concentration. Practical application of perovskite glass-ceramics as a radiation converter is shown in the paper.

The detection of humidity plays a vital role in healthcare, industrial, and scientific areas, and the development of an ideal sensor is in continuous progress. In this work, a relative humidity (RH) optical sensor based on localized surface plasmon resonance of self-assembled gold nanoparticles formed by thermal dewetting and coated with Nafion fluoropolymer is under study. Sensor performance has been found to substantially depend on Nafion layer thickness. The best sensing element—an array of gold nanoparticles covered with a 300 nm-thick Nafion—has been shown to possess a linear response in a wide dynamic range of 0–85% RH with a limit of detection down to 0.12%. Thus, a simple and low-cost method for high-accuracy RH detection has been demonstrated.

For the first time, the synthesis, luminescent and structural properties of stable perovskite-type (Cs1−xRbx)4PbBr6 (R = Cs, Rb) nanocrystals are shown. In the absence of rubidium, Cs4PbBr6 and CsPbBr3 perovskite crystals precipitate in the ZnO–Na2O–B2O3–GeO2 glass matrix. With ascending rubidium content, the precipitation of (Cs,Rb)4PbBr6 nanocrystals is replaced by the Rb4PbBr6 nanocrystals nucleation. Nucleated nanocrystals exhibit an intense green luminescence. With an increase of the rubidium content, the luminescence maximum shifts to the blue region, the luminescence quantum yield increases from 28 to 51%, and the average decay time increases from 2 to 8 ns. Several assumptions have been made about the nature of the green luminescence of perovskite-like Cs4PbBr6 and (Cs,Rb)4PbBr6 crystals in glasses. It is concluded that the most probable cause is the impurity inclusions of CsPbBr3 and (Cs,Rb)PbBr3 crystals.

Metal organic decomposition (MOD) for the metal oxides thin films fabrication has been used in various studies over the past 30 years. MOD is a simple and inexpensive method for manufacturing optical grade polycrystalline thin films, including bismuth-substituted yttrium iron garnet. We present a variant of the previously described MOD method and discuss a chemical route for fabricating thin porous oxide films with a thicknesses of more than 100 nm, which non-epitaxially crystallized on fused silica substrates into BixY3-xFe5O12 layers (x = 0.5 and 1.5). Studies of the structural and magneto-optical properties of the layers show that the garnet layers crystallized under optimal conditions are characterized by high values of the specific Faraday rotation. Importantly, crystallization can be done locally by laser irradiation, and wet etching makes possible to remove non-crystallized areas, thus extending microfabrication capabilities.

Rapid thermal annealing (RTA) at 800-900 ? in air atmosphere is commonly used to crystallize bismuth-substituted yttrium iron garnet (Bi:YIG) deposited by vacuum evaporation techniques or metal-organic decomposition. However, the conventional RTA leads to undesirable effects in applications where Bi:YIG is the constituent material of a nano- or microstructure. Here we report on an approach to Bi:YIG local crystallization by a focused continuous wave laser beam (LRTA). The structural and optical properties of micron-sized Bi:YIG stripes crystallized in air, oxygen, nitrogen and argon atmospheres are discussed. The demonstrated LRTA can find practical applications for Bi:YIG monolithic integration on non-garnet substrates.

The composition of materials in a micro-/nano-devices plays a key role in determining their mechanical, physical, and chemical properties. Especially, for devices with a compositional change on nanoscale which can often be achieved by point-by-point direct writing technology using a focused ion beam (FIB), electron beam (EB), or laser beam (LB), but so far, nanoscale composition analysis of a large-area micro/nano structures with a variation composition remains a big challenge in cost, simpleness, and flexibility. Here we present a feasible route to realize large-area composition analysis with nanoscale spatial resolution by using Raman spectroscopy. We experimentally verified the capability of this method by analyzing a complex Sn-SnOx system of a microscale grayscale mask with nanoscale spatial resolution of composition. Further analyses using Auger electron spectroscopy, transmission electron microscopy, and atomic force microscopy indicated the effectiveness and practicality of our method. This work opens up a way to analyze the composition of a large-area complex system at a nanoscale spatial resolution, and the method can be extended to many other material systems.

Femtosecond laser crystallization of magneto-optical bismuth substituted yttrium iron garnet (Bi/YIG) from an oxide film synthesized by the metal-organic decomposition method was demonstrated and studied. The maximum of the specific Faraday rotation of Bi/YIG films crystallized by laser pulses and that crystallized by conventional thermal annealing was shown to be 11 deg/mu m at 515 nm for both types. In cases where Bi/YIG is a functional layer of a multilayered structure on a substrate, the proposed approach allows us to overcome limitations related to overheating of the structure and the substrate occurring during conventional high-temperature annealing.

Advances in plasmonics have been fundamentally rooted in minimizing ohmic losses in metallic nanostructures. However, the losses at resonance can play a positive role; for instance, in optical heating, there are two sides to every story. Under laser illumination, plasmonic nanostructures serve not only as near-field enhancers but heat generators. The emerging field of thermoplasmonics opens up unprecedented possibilities to probe temperature-dependent phase transitions locally. In this paper, we develop a new approach behind plasmon-assisted optical heating for spectroscopically recognizing the glass transition temperature (T-g) of spatially confined poly(methyl methacrylate) (PMMA) polymers deposited on a square-shaped titanium nitride (TiN) pad. A local photoheating is controlled through Raman thermometry of a c-Si (100) substrate that functions as a temperature-sensing Raman reporter. The reliability of temperature measurements is corroborated by using both the anti-Stokes/Stokes ratio and the Raman peak shift. We show that optical heating can be adjusted by extruding a c-Si substrate, for example, the temperature increase is achieved by making c-Si pillars beneath the TiN pads longer. This peculiarity gives the possibility to probe the T-g in a broad temperature range for the diversity of glassy polymers. We believe that the developed method will pave the way for 2D mapping structural glass transitions of heterogeneous glassy polymers, polymeric blends, and eventually, 3D confined polymers.

The formation process for planar solid electrolytes in the CeO2-Y2O3 system has been studied using efficient, high-performance, high-resolution microplotter printing technology, using functional ink based on nanopowders (the average size of crystallites was 12-15 nm) of a similar composition obtained by programmed coprecipitation of metal hydroxides. The dependence of the microstructure of the oxide nanoparticles obtained and their crystal structure on yttrium concentration has been studied using a wide range of methods. According to X-ray diffraction (XRD), the nanopowders and coatings produced are single-phase, with a cubic crystal structure of the fluorite type, and the electronic state and content of cerium and yttrium in the printed coatings have been determined using X-ray photoelectron spectroscopy (XPS). The results of scanning electron (SEM) and atomic force microscopy (AFM) have shown that the coatings produced are homogeneous, they do not contain defects in the form of fractures and the height difference over an area of 1 mu m(2) is 30-45 nm. The local electrophysical characteristics of the oxide coatings produced (the work function of the coating surface, capacitance values, maps of the surface potential and capacitive contrast distribution over the surface) have been studied using Kelvin-probe force microscopy (KPFM) and scanning capacitive microscopy (SCM). Using impedance spectroscopy, the dependence of the electrophysical characteristics of printed planar solid electrolytes in the CeO2-Y2O3 system on yttrium content has been determined and the prospects of the technology developed for the manufacture of modern, intermediate-temperature, solid oxide fuel cells have been demonstrated. (C) 2020 Elsevier Inc. All rights reserved.

The effects of enhancement of stimulated Raman scattering in titanium oxynitride (TiON) nanofilms are considered. The mechanism of giant amplification of a Stokes wave is based on, first, localized plasmon resonance in titanium nitride (TiN) nanoparticles and, second, a spectrally degenerate behavior of the real part of the dielectric constant of the nanocomposite film. The enhancement of stimulated Raman scattering in the TiON film by means of a plasmonic nanoantenna and a nanostructured surface of the TiON film is demonstrated experimentally.

We used transmission electron microscopy, Raman, and photoluminescence spectroscopy to identify the effect of CuPt-type GaP-InP atomic ordering (AO) on the structural and emission properties of self-organized (SO) InP/GaInP2 Wigner molecule (WM) quantum dot (QD) structures. We found that the correlation of AO and SO growth results in the formation of InP/GaInP2 QD/AO-domain (QD/AOD) core-shell composites. This observation shows that intrinsic WMs in this system emerge due to a strong piezoelectric field generated by AODs, which induces QD doping and a built-in magnetic field. We found that the bond relaxation of AODs leads to a decrease in the emission energy of WMs of 80 meV. The photoluminescence spectra of single WMs having an emission energy ∼1.53 eV are presented here, the lowest one reported for this system.

We report a realization of room temperature lasing threshold of 1 μW in GaInP microdisk containing a few self-aggregated InP/GaInP quantum dots (QDs) grown by metal-organic vapor phase epitaxy. InP/GaInP QD microdisk cavities emitting in the spectral range of 700–800 nm and having the size of ~2 μm, free spectral range of ~35 nm and quality factors Q ~ 4000 were formed by wet chemical etching. Low dot density (~2 μm –2 ) and large dot size (~150 nm), suggesting a single dot lasing and maximum overlap of QD and cavity mode, were achieved using deposition of 3 ML of InP layer at 700°C.

We investigated structural and emission properties of self-organized InP/GaInP quantum dots (QD) grown by metal organic chemical vapor deposition using an amount of deposited In from 7 to 2 monolayers (ML). In the uncapped samples, using atomic force microscopy (AFM), we observed lateral sizes of 100–200 nm, together with a bimodal height distribution having maxima at ∼5 and ∼15 nm, which we denoted as QDs of type A and B, respectively; and reduction of the density of the type-B dots from 4.4 to 1.6 μm –2 . The reduction of the density of B-type dots were observed also using transmission electron microscopy of the capped samples. Using single dot low-temperature photoluminescence (PL) spectroscopy we demonstrated effects of Wigner localization for the electrons accumulated in these dots.

New trends in development of scanning microscopy and atomic force microscopy are considered. Micro- and nanoelectronics with extra high-level metrology requirements and up to material science, biology, and ecology with requirements to the side of simplification in operation procedures, possibility of the materials and molecules recognitions are discussed. Perspective ways of nanoscale methods development are proposed.

Structural and emission properties of few-electron In(Ga) P/GaInP quantum dots (QDs) representing natural Wigner molecules (WM) and whispering gallery mode (WGM) electron (e) cavities have been investigated. QD structures were grown using self-organized metal-organic vapor phase epitaxy and deposition from similar to 3 to 7 monolayers of InP at 700 degrees C. Using atomic force microscopy, transmission electron microscopy, near-field scanning optical microscopy (NSOM), and mu-photoluminescence (mu-PL) spectra we obtained In(Ga) P/GaInP QDs having lateral size 80-180 nm, height 5-30 nm, Ga content 0.0-0.4, density 2-10 mu m(-2), and electron population up to 20 and demonstrated control of their density and size distribution. Using high-spatial-resolution low-temperature PL spectra, NSOMimaging, and calculations of charge density distributions we observed Wigner localization and e-cavity effects for a series of dots having quantum confinement h omega(0) = 0.5-6 meV. We used these data together with time-resolved PL measurements to clarify the effect of Coulomb interaction and WM formation on emission spectra of few-electron QDs. We present direct observation of 2e, 6e, and 9e WMs; 2e and 4e WGMs; and Fabry-Perot e modes and establish conditions of e-WGM-cavity formation in these QDs.

The operating principles of an apertureless scanning near-field optical microscope (ASNOM) are described. The metalized needle of an atomic force microscope is a probe in the device, and the optical interaction with objects on the surface is localized near its tip, which is a few nanometers in size. The needle’s body is several microns long, ensuring high efficiency of its electromagnetic interaction with the light waves incident on it from the outside and emitted by it into space. The nano-antenna formed by the needle thus raises the efficiency of the optical interaction between nano-objects and the electromagnetic ether by 4–5 orders of magnitude. Results from scanning semiconductor and polymer structures are presented that demonstrate the ability of ASNOM to produce high-contrast images of objects’ optical properties (absorption, reflection, and thermal expansion) with resolutions of 10–50 nm, regardless of wavelength.