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On an example of a service for merged SST charts computing, the problems of integrating a sophisticated technology of external provider into the Roscosmos State Information System for the Operational Delivery of Earth Remote Sensing Data (SIS OD ERS) are considered. The main goal of the SIS OD ERS is the implementation of a simple and uniform access to satellite data of both Russian and worldwide archives, as well as to high-level processing products in a required thematic area. External provider gets access to satellite data archives and computing resources of SIS OD ERS. The key issue is minimizing the cost of processing data from both Roscosmos and external providers. The Multiple Access Center for Regional Satellite Monitoring of the Environment of the Far East Branch of the Russian Academy of Sciences deploy its services to SIS OD ERS. The options for arranging the exchange of data and services between a provider and SIS OD ERS are proposed. A REST web services are made, with its support in the Python environment. As a result of the integration, daily merged SST charts are built that preserve the structure of thermal fronts for any water area and with the accuracy that corresponds the international standards. The service is distributed. Both the resources and data of Roscosmos and the Satellite Center of the Far Eastern Branch of the Russian Academy of Sciences, and the data from the foreign information systems are used.

Bilirubin (BR) is a product of hemoglobin breakdown, and its increasing levels in the blood may indicate liver disorders and lead to jaundice. Kernicterus is most dangerous in newborns when the unconjugated BR concentration can quickly rise to toxic levels, causing neurological damage and even death. The development of an accurate, fast, and sensitive sensor for BR detection will help reduce diagnostic time and ensure successful treatment. In this study, we propose a new method for creating a surface-enhanced Raman scattering (SERS)-active substrate based on gold-decorated silicon nanowires (Au@SiNWs) for sensitive label-free BR detection. Gold-assisted chemical etching of crystalline silicon wafers was used to synthesize SiNWs, the tops of which were then additionally decorated with gold nanoparticles. The low detection limit of model analyte 4-mercaptopyridine down to the concentration of 10-8 M demonstrated the excellent sensitivity of the obtained substrates for SERS application. The theoretical full-wave electromagnetic simulations of Raman scattering in the Au@SiNW substrates showed that the major contribution to the total SERS signal comes from the analyte molecules located on the SiNW surface near the gold nanoparticles. Therefore, for efficient BR adsorption and SERS detection, the surface of the SiNWs was modified with amino groups. Label-free detection of BR using amino modified Au@SiNWs with high point-to-point, scan-to-scan, and batch-to-batch reproducibility with a detection limit of 10-6 M has been demonstrated. Artificial urine, mimicking human urine samples, was used as the matrix to get insights into the influence of different parameters such as matrix complexity on the overall BR SERS signal. The signal stability was demonstrated for 7 days after adsorption of BR with a concentration of 5 × 10-5 M, which is the required sensitivity for clinical applications.

Introduction. This psychological research addresses the problem of motivational-value self-organization of teachers and students in education. The purpose of the article is to determine the features of motivational and value self-organization of teachers and students in the post-Soviet educational environment. Materials and Methods. The research was conducted from 2002 to 2020 on the basis of higher education institutions and secondary schools in Ukraine (Donbass, the Nikolaev Region) and the Crimea. The sample consisted of 2128 people including students doing degrees in the fields of Humanities, Law, Economics, and Engineering; secondary school teachers and students; academic staff of higher education institutions. The study has investigated the constructs of motivational-value self-organization of teachers and students in terms of meaning of life orientations. The author developed and used ‘motivational-value self-organization inventory’ in order to disclose levels and types of personal values as well as factors determining personal life goals. Results. The main research findings are that (1) ‘Individual pragmatic type’ of motivational-value self-organization predominates among value orientations of teachers and students (education, work, happiness in private life, housing and material well-being, health, etc.); (2) teachers and students are not focused on social (public achievements and problems), cultural (existence and civilization) or moral values. (3) Students are more optimistic about self-fulfillment and more internal in clarifying their life goals. Conclusions. The article concludes that motivational-value self-organization being a personal quality is developed within the sociocultural environment (educational semantic space) which determines personal identity.

In this paper, we theoretically and experimentally study the reflection and photoluminescence spectra angular dependencies of the two-dimensional gold nanodisk array on top of thin luminescent layer. Hydrogenated amorphous silicon-carbon alloy was used as a luminescent material with a high refractive index in the visible spectral range. Angle-resolved optical spectra were measured by a Fourier imaging spectroscopy in p- and s-polarizations. Both transverse electric (TE) and transverse magnetic (TM) quasiguided modes are clearly seen in the reflection and photoluminescence spectra in both polarizations simultaneously.

We theoretically study Dyakonov surface waveguide modes that propagate along the planar strip interfacial waveguide between two uniaxial dielectrics. We demonstrate that owing to the one-dimensional electromagnetic confinement, Dyakonov surface waveguide modes can propagate in the directions that are forbidden for the classical Dyakonov surface waves at the infinite interface. We show that this situation is similar to a waveguide effect and formulate the resonance conditions at which Dyakonov surface waveguide modes exist. We demonstrate that the propagation of such modes without losses is possible. We also consider a case of two-dimensional confinement, where the interface between two anisotropic dielectrics is bounded in both orthogonal directions. We show that such a structure supports Dyakonov surface cavity modes. Analytical results are confirmed by comparing with full-wave solutions of Maxwell’s equations. We believe that our work paves the way toward new insights in the field of surface waves in anisotropic media.

The results of studies of the luminescence properties of two-dimensional photonic crystals formed on the basis of silicon structures with self-assembled Ge(Si) nanoislands are reported. The possibilities of substantially enhancing the luminescence response of the active medium (Ge(Si) nanoislands) in the wavelength range 1.2–1.6 μm are shown for such structures. The specific features of the luminescence response of a photonic crystal in the vicinity of the Γ point of its Brillouin zone are studied. It is shown that, along with the broadband response characteristic of the radiative modes of photonic crystals, high-Q resonances, for which the Q factor exceeds 103, can also be observed in such structures. The last-mentioned resonances are observed in a certain range of lattice parameters of photonic crystals.

Multilayer stacks of twisted optical metasurfaces are considered as a prospective platform for chiral nanophotonic devices. Such structures are primarily used for the realization of circularly polarized light sources, artificial optical rotation, and circular dichroism. At the same time, the behavior of their hybrid photonic modes is strongly affected by the moir\'e-pattern of superimposed periodic constituents. In this work, we show that moir\'e-periodicity in bilayer dielectric photonic crystal slabs leads to an arise of unlimitedly narrow optical resonances, which are very sensitive to the relative twist and gap width between the sublayers. We demonstrate the structure providing twist-tuning of the hybrid mode wavelength in the range of 300--600~nm with quality factor varying from~$10^2$~up~to~$10^5$ correspondingly. The obtained results pave the wave for the utilization of moir\'e-assisted effects in multilayer photonic crystal slabs.

Germanium quantum dots are promising but their photoluminescence intensity is still insufficient for practical applications. It is demonstrated that their PL in silicon photonic crystal slab can be dramatically enhanced due to the involvement of the bounds states in the continuum into the emission process.

In recent years twisted bilayers of two-dimensional (2D) materials have become very popular in the field due to the possibility to totally change their electronic properties by simple rotation. At the same time, in the wide field of photonic crystals, this idea still remains almost untouched, and only some particular problems have been considered. One of the reasons is the computational difficulty of accurate consideration of moir\'e superlattices that appear due to the superimposition of misaligned lattices. Indeed, the unit cell of the complex lattice is typically much larger than the original crystals and requires many more computational resources for the computations. Here, we propose a moir\'e-adapted Fourier modal method (MA-FMM) in the form of scattering matrices for the description of twisted one-dimensional (1D) gratings' stacks. We demonstrate that MA-FMM allows us to consider sublattices in close vicinity to each other and account for their interaction via the near field. In the developed numerical scheme, we utilize the fact that each sublattice is only 1D periodic and therefore simpler than the resulting 2D superlattice, as well as the fact that even a small gap between the lattices filters out high Fourier harmonics due to their evanescent origin. Such approach accelerates the computations from 1 up to 3 or more orders of magnitude for typical structures depending on the number of harmonics. In turn, the high computational speed paves the way for rigorous study of almost any photonic crystals of the proposed geometry and demonstration of specific moir\'e-associated effects.

We study theoretically and experimentally a magneto-optical Kerr effect (TMOKE) in magnetite film covered by sub-wavelength grating consisting of gold nanostripes. Our rigorous coupled wave analysis (RCWA) simulations of optical reflection and transmission coefficients of the structure under study predict a multiple enhancement of TMOKE response in transmission as compared with a plain magnetite film without gold nanostripes. We demonstrate that due to the high absorption losses in magnetite film, the quality factors of the optical resonances in our sample are low which results in wide areas on the dispersion diagram where the TMOKE can be observed.

The great application potential of photoluminescent silicon nanocrystals, especially in biomedicine, is significantly reduced due to their limited radiative rate. One of the possible ways to overcome this limitation is enhancing the luminescence by localized plasmons of metallic nanostructures. We report an optimized fabrication of gold nanorod – silicon nanocrystal core–shell nanoparticles with the silica shell as a tunable spacer. The unprecedented structural quality and homogeneity of our hybrid nanoparticles allows for detailed analysis of their luminescence. A strong correlation between dark field scattering and luminescence spectra is shown on a single particle level, indicating a dominant role of the longitudinal plasmonic band in luminescence enhancement. The spacer thickness dependence of photoluminescence intensity enhancement is investigated using a combination of experimental measurements and numerical simulations. An optimal separation distance of 5 nm is found, yielding a 7.2× enhancement of the luminescence intensity. This result is mainly attributed to an increased quantum yield resulting from the Purcell enhanced radiative rate in the nanocrystals. The ease of fabrication, low cost, long-term stability and great emission properties of the hybrid nanoparticles make them a great candidate for bio-imaging or even targeted cancer treatment.

A new approach to improve the light-emitting efficiency of Ge(Si) quantum dots (QDs) by the formation of an ordered array of QDs on a pit-patterned silicon-on-insulator (SOI) substrate is presented. This approach makes it possible to use the same pre-patterned substrate both for the growth of spatially ordered QDs and for the formation of photonic crystal (PhC) in which QDs are embedded. The periodic array of deep pits on the SOI substrate simultaneously serves as a template for spatially ordering of QDs and the basis for two-dimensional PhCs. As a result of theoretical and experimental studies, the main regularities of the QD nucleation on the pre-patterned surface with deep pits were revealed. The parameters of the pit-patterned substrate (the period of the location of the pits, the pit shape, and depth) providing a significant increase of the QD luminescence intensity due to the effective interaction of QD emission with the PhC modes are found.

We theoretically predict the existence of Dyakonov-like surface waveguide modes in the planar interfacial waveguide between two uniaxial dielectrics and Dyakonov surface cavity modes in the interface of two anisotropic dielectrics with rectangular cross-sections.

We demonstrate that single-walled carbon nanotube (SWCNT) membranes can be successfully utilized as nanometer-thick substrates for enhanced visualization and facilitated study of individual nanoparticles. As model objects, we transfer optically resonant 200 nm silicon nanoparticles onto pristine and ethanol-densified SWCNT membranes by the femtosecond laser printing method. We image nanoparticles by scanning electron and bright-field optical microscopy, and characterize by linear and Raman scattering spectroscopy. The use of a pristine SWCNT membrane allows to achieve an order-of-magnitude enhancement of the optical contrast of the nanoparticle bright field image over the results shown in the case of the glass substrate use. The observed optical contrast enhancement is in agreement with the spectrophotometric measurements showing an extremely low specular reflectance of the pristine membrane (≤0.1%). Owing to the high transparency, negligibly small reflectance and thickness, SWCNT membranes offer a variety of perspective applications in nanophotonics, bioimaging and synchrotron radiation studies.

Resonant modes are important characteristics of the optical properties of photonic crystals since they are responsible for the features in the transmission and reflection spectra as well as the emissivity of quantum emitters inside such structures. We present a resonant modes expansion method applied to a problem of radiating dipoles inside a photonic crystal. In stacked photonic crystal slabs, there is a coupling between the resonances of distinct subsystems and Fabry–Perot resonances. We propose a technique to calculate the coefficients of resonant mode expansion based on the scattering matrix formalism of the Fourier modal method (FMM). The method appears to be convenient since it does not require rigorous normalization of resonant fields or application of perfectly matched layers. Then, we demonstrate the agreement between the resonant modes expansion results and exact FMM solutions.

Resonant structure consisting of waveguide layer with metallic strips array is a promising design for various optical effects control and enhancement at the nanoscale due to its strong resonant properties and light localization phenomena. However, different applications require understanding the nature of eigenmodes of the structure, that possess peculiar properties. In this research, the optical properties of the planar waveguide with one-dimensional periodic gold grating on it was examined. Emitting layer of a-Si1-xCx:H was deposited by plasma chemical vapour deposition technique and the gold array was created by the e-beam lithography. Angle-resolved reflection and photoluminescence spectra in s- and p-polarizations were measured by the Fourier-imaging spectroscopy method. The theoretical analysis was performed to reveal the physical nature of the observed spectral features and their effect on the waveguide layer emitting properties was studied.

The ease of fabrication, large surface area, tunable pore size and morphology as well surface modification capabilities of a porous silicon (PSi) layer make it widely used for sensoric applications. The pore size of a PSi layer can be an important parameter when used as a matrix for creating surface-enhanced Raman scattering (SERS) surfaces. Here, we evaluated the SERS activity of PSi with pores ranging in size from meso to macro, the surface of which was coated with gold nanoparticles (Au NPs). We found that different pore diameters in the PSi layers provide different morphology of the gold coating, from an almost monolayer to 50 nm distance between nanoparticles. Methylene blue (MB) and 4-mercaptopyridine (4-MPy) were used to describe the SERS activity of obtained Au/PSi surfaces. The best Raman signal enhancement was shown when the internal diameter of torus-shaped Au NPs is around 35 nm. To understand the role of plasmonic resonances in the observed SERS spectrum, we performed electromagnetic simulations of Raman scattering intensity as a function of the internal diameter. The results of these simulations are consistent with the obtained experimental data.

There has been growing interest in recent years in developing multifunctional materials for studying the structure interface in biological systems. In this regard, the multimodal systems, which possess activity in the near-infrared (NIR) region, become even more critical for the possibility of improving examined biotissue depth and, eventually, data analysis. Herein, we engineered bi-modal contrast agents by integrating carbon nanotubes (CNT) and gold nanoparticles (AuNP) around silica microspheres using the Layer-by-Layer self-assembly method. The experimental studies revealed that microspheres with CNT sandwiched between AuNP exhibit strong absorption in the visible and NIR regions and high optoacoustic contrast (OA, also called photoacoustics) and Raman scattering when illuminated with 532 nm and 785 nm lasers, respectively. The developed microspheres demonstrated amplification of the signal in the OA flow cytometry at the laser wavelength of 1064 nm. This finding was further validated with ex vivo brain tissue using a portable Raman spectrometer and imaging with the Raster-scanning OA mesoscopy technique. The obtained data suggest that the developed contrast agents can be promising in applications of localization OA tomography (LOT), OA flow cytometry, and multiplex SERS detection.

Stimuli-responsive polymers have attracted increasing attention over the years due to their ability to alter physiochemical properties upon external stimuli. However, many stimuli-responsive polymer-based sensors require specialized and expensive equipment, which limits their applications. Here an inexpensive and portable sensing platform of novel microarray films made of stimuli-responsive polymers is introduced for the real-time sensing of various environmental changes. When illuminated by laser light, microarray films generate diffraction patterns that can reflect and magnify variations of the periodical microstructure induced by surrounding invisible parameters in real time. Stimuli-responsive polyelectrolyte complexes are structured into micropillar arrays to monitor the pH variation and the presence of calcium ions based on reversible swelling/shrinking behaviors of the polymers. A pH hysteretic effect of the selected polyelectrolyte pair is determined and explained. Furthermore, polycaprolactone microchamber arrays are fabricated and display a thermal-driven structural change, which is exploited for photonic threshold temperature detection. Experimentally observed diffraction patterns are additionally compared with rigorous coupled-wave analysis simulations that prove that induced diffraction pattern alterations are solely caused by geometrical microstructure changes. Microarray-based diffraction patterns are a novel sensing platform with versatile sensing capabilities that will likely pave the way for the use of microarray structures as photonic sensors.

The utilization of periodic structures such as photonic crystals and metasurfaces is common for light manipulation at nanoscales. One of the most widely used computational approaches to consider them and design effective optical devices is the Fourier modal method (FMM) based on Fourier decomposition of electromagnetic fields. Nevertheless, calculating periodic structures with small inclusions is often a difficult task since they induce lots of high-${k}_{\ensuremath{\parallel}}$ harmonics that should be taken into account. In this paper, we consider small-particle lattices with bases (complex unit cells) and construct their scattering matrices via discrete dipole approximation. Afterwards, these matrices are implemented in FMM for consideration of complicated layered structures. We show the performance of the proposed hybrid approach by its application to a lattice, which routes left and right circularly polarized incident light to guided modes propagating in opposite directions. We also demonstrate its precision by spectra comparison with finite-element method calculations. The high speed and precision of this approach enable the calculation of angle-dependent spectra with very high resolution in a reasonable time, which allows resolving narrow lines unobservable by other methods.

We propose a perfect photonic router based on a specially designed chiral bi-metasurface membrane for spin-polarized point light sources. Due to the mirror symmetry breaking in the chiral metamembrane, the radiation power flux of the clockwise and counterclockwise spinning dipoles to the opposite sides of the slab becomes different. We show that spinning dipoles in the specially designed chiral D$_4$-symmetrical bi-metasurface membrane can emit light either upwards or downwards depending on their rotation direction. We attribute this phenomenon to the Fano-resonance effect which is a result of the guided modes coupling with the far field. We show the advantage of D$_4$-symmetrical structures for the achievement of 100\% routing efficiency. This phenomenon can find applications in spintronics for spin-selective inter-chip coupling or as a measurement tool of spin polarization in memory cells., Comment: 6 pages, 5 figures

In this work, we study theoretically and experimentally the reflection and photoluminescence spectra of SiC slab waveguide with a two-dimensional plasmonic lattice of gold nanodisks. We demonstrate the appearance of the plasmonic modes in the lattice and their interaction with guided modes in SiC slab. Experimental reflection and photoluminescence spectra are in agreement with theoretical predictions.

Plasmonic nanoparticles lattices in a dielectric environment demonstrate exceptional optical properties due to the combination of plasmonic structures’ ability to confine light in deep subwavelength scale and dielectric ones to support high-quality optical modes. However, such structures, especially in the case of the small size of plasmonic particles, are hard for the calculation by the means of the Fourier modal method (FMM) specialized for periodic structures, since their local field is described by high-k|| harmonics. We propose not to account for a large number of harmonics, but to consider the lattice in discrete dipole approximation (DDA) to construct its scattering matrix. In this work, we apply this approach for lattices with several particles in a cell. The performance of the method is demonstrated on an example of the lattice on a waveguide that supports polarization controlled coupling of circularly polarized light to guided modes propagating in opposite directions. We show the high speed and precision of our approach, which allows us to use it both for the calculation of plasmonic lattices spectra and the design of nanophotonic devices based on such lattices.

The transverse magneto-optical Kerr effect (TMOKE) in magnetite-based magneto-plasmonic crystals is studied experimentally and theoretically. We analyze angle-resolved TMOKE spectra from two types of structures where noble metallic stripes are incorporated inside a thin magnetite film or located on top of a homogeneous film. A multiple wide band enhancement of the TMOKE signal in transmission is demonstrated. The complex dielectric permittivity and gyration are experimentally determined using the ellipsometry technique as well as Faraday rotation and ellipticity measurements. The obtained parameters are used in rigorous coupled wave analysis (RCWA) calculations for studying the optical resonances. Our RCWA calculations of transmittance and TMOKE are in good agreement with the experimental data. The role of guiding and plasmonic modes in the TMOKE enhancement is revealed. We demonstrate that the TMOKE provides rich information about the studied optical resonances., Comment: 12 pages, 10 figures

More than an order of magnitude enhancement of the room-temperature photoluminescence (PL) signal from rather thick germanium layers grown on Si(001) was obtained through the utilization of 2D photonic crystals (PhCs). A set of PhCs with different periods and filling factors was fabricated and studied using micro-PL spectroscopy. Optical features of the fabricated PhCs were also theoretically modeled using rigorously coupled wave analysis, which allowed us to bring the observed peaks in the PL response into correlation with the different modes of PhC. In particular, we were able to associate the well-resolved peaks in the PL spectra with the optically active modes of the PhCs. The obtained results proved the possibility of using a homogeneously distributed active medium in PhCs without the formation of specially designed cavities in order to redistribute the internal emitted light into the required modes and efficiently extract it in the far field. The relative simplicity and higher tolerance to fabrication imperfections, as well as the large working area of these kinds of PhCs compared to PhCs with microcavities, can be advantageous for creating a PhC-based Si-compatible light source for the telecom band.

Optical properties of tensile strained n-doped Ge microstructures were investigated. Formation of microresonators based on Bragg reflectors and photonic crystals were implemented for such kind of active medium and opportunities to employ them for fabrication of efficient Si-compatible light sources were discussed.

The strong enhancement of photoluminescence intensity was observed in photonic crystal slabs realized on Si structures with the self-assembled Ge nanoislands. The observed phenomena are described in terms of the nanoislands — photonic crystal modes interaction.

Rigorous coupled-wave analysis (RCWA) is a very effective tool for the studying optical properties of multilayered vertically invariant periodic structures. However, it fails to deal with arrays of small particles because of high gradients in a local field. In this thesis, we implement discrete dipole approximation (DDA) for the construction of scattering matrices of arrays of resonant nanoparticles. This strongly speeds up the calculations and therefore provides an opportunity for thorough consideration of various layered structures with small periodic inclusions in terms of the RCWA. We study in detail three main stages of the method: calculation of polarizability tensor of a single nanoparticle, effective polarizability of this particle in a lattice and corresponding scattering matrix of the layer for further integration in the conventional RCWA approach. We demonstrate the performance of the proposed method by considering plasmonic lattices embedded in a homogeneous ambiance and placed inside and onto optical waveguides and compare our results with experimental papers. Such phenomena as localized surface plasmon resonances (LSPRs) and lattice plasmon resonances (LPRs) are observed as well as their hybridization with photonic guided modes. High accuracy and fast convergence of our approach are shown by a comparison with other computational approaches. Typical limits of applicability of our approximate method are determined by an exploration of the dependence of its error on the parameters of the structure.

The aim of the investigation is to consider a problem of stress resistance of students in the context of subject self-organization of the personality. Methods . The following methods of research are used: questioning; psychological and diagnostic tests «Tolerance of Uncertainty» (NTN) and «Personal Factors of Decisions» (PFD) by T. V. Kornilova; original experimental experiences – «Coding», a technique of a self-assessment (scaling) and «A locus control». While data processing the methods of mathematical statistics (SPSS 12 package) – the correlation analysis of Pearson and the factorial analysis with rotation use a component by «verimax» method are applied. Results and scientific novelty. Types of subjectivity and strategy of stress resistance are allocated. The nature and a role of the emotional and stressful mechanism having information and semantic properties in its basis are disclosed. Communication of irresponsible mechanisms of mentality with the sphere of consciousness in the context of subjectivity of the personality is shown. Mechanisms of emotional and rational self-control of system of mental self-organization of the person are presented. The statistical and qualitative data opening communications between properties of subjectivity and stress resistance of the personality are empirically obtained. Variation of the relations and also types of subjectivity and stress resistance emphasized based on the results of the presented research. Original (author’s) methods of studying of subjectivity and factors of stress resistance are presented. Practical significance. The revealed factors of subject self-organization reveal the stress-producing directions of the environment and the relation of the personality to situations of changes and uncertainty: and also indicate subject properties of resistance to stress which need to be developed to increase the level of health of students, to reduce risk of deviance and delinquency of their behavior.

In this study reflection and photoluminescence spectra of a-Si:C:H thin film with gold grating on it was examined theoretically and experimentally. The hydrogenated amorphous amorphous silicon-carbon alloy films were fabricated by the PECVD technique. Arrays of gold stripes with different gold width were created by lift-off e-beam lithography. Reflection, and PL spectra has been measured by a Fourier imaging spectroscopy. The theoretical calculations are in a good agreement with experimental results. From the PL spectra it follows, that the TE polarization gives sharper and more efficient PL signal than the TM polarization, and PL efficiency almost does not depend on gold stripes widths. It was shown that only in TE modes the PL outcouples from the gratings owing to the fact that there is no plasmon’s affect in this polarization.

Transverse magneto-optical Kerr effect (TMOKE) is known to be an effective tool for external magnetic field control of optical properties of magnetoplasmonic crystals. In some applications there is a demand for the pronounced TMOKE in the wide wavelength range. In this work we experimentally and theoretically demonstrate that a magnetite based magnetoplasmnic crystal exhibit a multiple wide band enhancement of TMOKE response in transmission compared to a plain magnetite film without metal. Our RCWA calculations are in good agreement with experimental results.

Fourier modal method (FMM) proved itself as an effective technique for investigation of layered periodic structures. However, it fails to deal with arrays of small particles because of high gradients in a local field. In this paper, we demonstrate the capability of the method, which is based on the construction of scattering matrices of arrays of resonant nanoparticles semianalytically in discrete dipole approximation (DDA). This approach is much faster than conventional ones and therefore provides an opportunity for thorough consideration of various layered structures with small periodic inclusions in terms of the RCWA. The performance of the considered method is demonstrated on an example of plasmonic lattices embedded in a homogeneous ambience and placed inside and onto an optical waveguide. Localized surface plasmon resonances (LSPRs), lattice plasmon resonances (LPRs) and their hybridization with photonic guided modes are observed. High precision of this calculations is confirmed by comparison with finite element method (FEM).

In this study the new approach to the efficiency evaluation of the transverse magneto-optical Kerr effect is considered. To assess the prospects for the practical use of structures based on TMOKE, the Figure of Merit (FOM) parameter is introduced, which is the product of the reflected/transmitted light intensity and the Kerr signal of the structure. Kerr signal defined as absolute value of the difference of light intensities at opposite magnetizations. It is shown that parameter Figure of Merit (FOM) in proposed form can give more information than the most commonly used relative value of TMOKE. The advantages of the introduced parameter are demonstrated on the example of a magnetoplasmonic structure with thin magnetite films.

In this study transverse magneto-optical Kerr effect in transmission for the magnetite thin film with gold grating on top was examined theoretically and experimentally. The magnetite films with thickness of 200 nm were fabricated by the laser electrodispersion technique. Arrays of gold stripes with 600 nm period and 350 nm and 500 nm stripe widths were created by lift-off e-beam lithography. It was shown experimentally that the TMOKE enhancement in structures with 350 nm width is attributed to SPP excitation on gold-magnetite surface. TMOKE value δ reaches magnitude of ±5·10−3 at the wavelengths 790 nm and 860 nm at light incidence angles of 8-10° and 12-13°, respectively. In case of 500 nm stripe width, SPP excitation is poor, however δ reaches magnitude of ±6.6·10−3 at angles of incidence more than 20°, that can be associated with the quasiguided mode resonance in such structure.

Carbon nanotubes (CNT) are being intensively studied for many applications because of their unique properties, such as high electrical and thermal conductivities, excellent mechanical and chemical stability. One of the areas of CNT application is a bolometric detection of near- and mid-infrared (IR) radiation. The record near-IR bolometric performance of CNT devices is comparable to the performance of the commercial vanadium oxide detectors [1]. However, the low intrinsic absorption of CNT in the mid-IR range limits their applications for the detection in the crucial 3-5 µm and 8-12 µm regions. The phenomenon of surface plasmon excitation has been utilized to improve light harvesting efficiency of solar cells and to increase absorption of monolayer graphene [2]. Plasmons were recently observed on an individual CNT [3], but the excitation of a surface plasmon on the macroscopic CNT films have not been reported yet. In the study, we experimentally demonstrate the 100%-enhanced bolometric response of a single-walled carbon nanotube (SWCNT) film in the vicinity of a mid-IR surface plasmon resonance. As a basis for the sample we use a pristine SWCNT film with the thickness of 400 nm, the width of 3 mm, and the length of 6 mm, suspended between two gold contacts. The femtosecond laser is used to drill 3- µm round holes which are arranged in a 2D square lattice with a period of 10 µm. Only one half of the film (3x3 mm2) is structured, while the second half is left unstructured to perform reference measurements. Reflectance and transmittance spectra of both parts of the film are measured with the Fourier-transform infrared spectrometer in the range 2-100 µm. Surface plasmon manifests itself as a Fano-type resonance in spectra of the structured part of the film at the wavelengths around 15 µm. The absorption of the structured part is enhanced in the same spectral region by 75% as compared with the unstructured part. Spectral dependence of the bolometric voltage sensitivity is measured using the sample as a detector of the spectrometer. It is shown that the voltage response of the structured part is enhanced in the vicinity of the surface-plasmon resonance by 100%. We show that the wavelength of the resonance and its magnitude can be controlled by tailoring the geometry of the sample. Numerical calculations by scattering-matrix method show that the central wavelength of the absorption resonance can be tuned in the range 5-25 µm. The maximum available enhancement of absorption is 240% as compared with the unstructured film. We claim that the proposed method applies to achieve enhanced spectrally selective response for any CNT-based bolometer in both near- and mid-infrared ranges of the spectrum. [1] G. E. Fernandes, J. H. Kim, A. K. Sood, J. Xu, Adv. Funct. Mater. 2013, 23, 4678. [2] N. K. Emani, T.-F. Chung, A. V Kildishev, et al. Nano Lett. 2013, 14, 78. [3] Z. Shi, X. Hong, H. A. Bechtel, et al. Nat. Photonics 2015, 9, 515

We report on the results of theoretical and experimental studies of photoluminescense of silicon nanocrystals in the proximity to plasmonic modes of different types. In the studied samples, the type of plasmonic mode is determined by the filling ratio of a one-dimensional array of gold stripes which covers the thin film with silicon nanocrystals on a quartz substrate. We analyze the extinction, photoluminesce spectra and decay kinetics of silicon nanocrystals and show that the incident and emitted light is coupled to the corresponding plasmonic mode. We demonstrate the modification of the extinction and photoluminesce spectra under the transition from wide to narrow gold stripes. The experimental extinction and photoluminescense spectra are in good agreement with theoretical calculations performed by the rigorous coupled wave analysis. We study the contribution of individual silicon nanocrystals to the overall photoluminescense intensity, depending on their spacial position inside the structure.

We report an experimental observation of the midinfrared surface plasmon excited in a carbon nanotube plasmonic metasurface. The absorption of a 400-nm-thick single-walled carbon nanotube film perforated with laser-drilled subwavelength holes arranged in a 2D lattice is resonantly enhanced by 75% as compared with the unstructured film. The enhancement of absorption has a resonant behavior associated with the excitation of the surface plasmon and occurs at the wavelengths around 15 μm for the lattice period of 10 μm. The spectral position and the magnitude of the resonance are controlled entirely by the structure geometry and can be tuned in a broad range. We demonstrate that periodic patterning can be applied to tailor the bolometric performance of carbon nanotube thin films. Namely, the voltage response of the metasurface is enhanced by 100% at the wavelength of the plasmon resonance as compared with the unstructured film. We discuss mechanisms of the enhancement and compare experimental results with the finite-difference time-domain and scattering-matrix method simulations.

Thermal radiation from bulk disorderly placed nonresonant emitters is incoherent, broadband and isotropic. In an external magnetic field the thermal radiation from any source is circularly polarized. Here we propose a thermal radiation source which emits circularly polarized radiation and which is not placed in a magnetic field. The thermal source consists of a slab waveguide with etched chiral metasurface. Due to the absence of a mirror symmetry of the metasurface, the thermally generated electromagnetic waves become circularly polarized. In this letter we discuss the origin of this phenomenon in details. Using the Fourier modal method we analyze the eigenmodes of the structure and the emissivity spectra. We demonstrate that the degree of circular polarization in an optimized structure can be as high as 0.87., Comment: 6 pages, 6 figures