Optomechanical manipulation with hyperbolic metasurfaces

Auxiliary nanostructures introduce additional flexibility into optomechanical manipulation schemes. Metamaterials and metasurfaces capable to control electromagnetic interactions at the near-field regions are especially beneficial for achieving improved spatial localization of particles, reducing laser powers required for trapping, and for tailoring directivity of optical forces. Here, optical forces acting on small particles situated next to anisotropic substrates, are investigated. A special class of hyperbolic metasurfaces is considered in details and is shown to be beneficial for achieving strong optical pulling forces in a broad spectral range. Spectral decomposition of the Green functions enables identifying contributions of different interaction channels and underlines the importance of the hyperbolic dispersion regime, which plays the key role in optomechanical interactions. Homogenised model of the hyperbolic metasurface is compared to its metal-dielectric multilayer realizations and is shown to predict the optomechanical behaviour under certain conditions related to composition of the top layer of the structure and its periodicity. Optomechanical metasurfaces open a venue for future fundamental investigations and a range of practical applications, where accurate control over mechanical motion of small objects is required

Prospects for the Use of Private Sector Capital in the Development of High-Tech Industry

Relevance: The solution to the problems of competitiveness of innovative technologies and products in global markets, accelerating the process of import substitution (if existing international economic sanctions by Russia) perhaps with the active using the capital of private business. This calls for the formation of certain financial and economic conditions of overcoming the barriers of innovative development of enterprises. The novelty of the present scientific research is in the following: the main vectors of transformation of innovative development of high-tech industrial enterprises, the necessity of wide use of capital of private business in the form of portfolio investments co-financed by the innovative projects. Practical usefulness. The increase in the share capital of private business in implementing innovative programs will reduce the financial burden on the federal budget. To increase the possibility of accelerating the processes of development of public-private partnerships and venture financing. Will expand the scope of use of the capital of private business in creating science-based dual-use products, implementation-oriented private commercial contracts in various sectors of the economy.  The future economic development of the country depends on the development and implementation of new technological researches that can make a certain breakthrough in providing technological and economic growth. The life cycle (LC) of any innovation embodied in specific correlation: Innovative idea → Conducting of fundamental research studies → R&D → Pilot production → Mass production → Gradual elimination of aging equipment and technology with better analogues

An economic value of the glycated hemoglobin test in diabetes mellitus type 2 diagnosis

BACKGROUND: Diagnostic of diabetes mellitus type 2 (DM2T) in time is very actual for treatment and prevention of potential complications of illness. Fasting blood glucose test (FBG) is a widely used method of primary DM2T diagnose. Glycated hemoglobin (HbA1c) test is an alternative and used more rarely due to expensive. AIM: Modelling of comparative expenditures for DM2T control in cases of primary diagnostic by HbA1c test or FBG test usage in 20-years horizon. METHODS: Retrospective analysis of aggregated epidemiological Russian NATION study data in 810 patients with prediabetes and DM2T with both analysis performed, with sensitivity and specificity of each is detected. The simulation model of DM2T outcomes has been used for Health Technology assessment (direct and indirect costs of Diabetes control during 20 years). Three algorithms of the DM2T treatment were investigated for understanding of expenditures in case on diagnostic on-time and case of late verification with metformin, gliflozines, gliptins, Glucagon-like peptide-1 receptor agonists, basal insulin analogs and their combinations. RESULTS: FBG test has more negative results for DM2T diagnostics in compare with HbA1c analysis (77,4% and 36,5% accordingly). Amount of false negative results in FBG test in 3 times more often occurred in comparison with HbA1c. HbA1c test in 3 times more precisely than FBG test for carbon metabolism abnormalities detection. Diagnostic in time with HbA1c test in compare with late process of illness detection by FBG can cut common expenditures on 26,3-27,7% depending on treatment option due to macrovasular complications decreasing. Disability rate is expected decrease on 21% to 20-th year in case of diagnostic with HbA1c performing instead FBG test. CONCLUSION: HbA1c test has diagnostic advantages in compare with FBG test for primary investigation (dispanserization). Direct and indirect expenditures in average for one patient with DM2T on 20-years horizon including cost of drugs, analysis, complications, disabilities are less in case of diagnostic in time with HbA1c test in comparison with late diagnostics in case of FBG test execution

«DIARISK» — the first national prediabetes and diabetes mellitus type 2 risk calculator

BACKGRAUND: The need to create a national questionnaire for screening the population for disorders of carbohydrate metabolism.AIMS: Develop a highly specific and sensitive questionnaire-calculator of the risk of prediabetes (PreD) and diabetes mellitus type 2 (DM2T) based on depersonalized data of individuals who have these diagnoses confirmed in the national epidemiological study NATION.METHODS: The express method of prediabetes (PreD) and diabetes mellitus type 2 (DM2T) risks has been created, validated and proposed for clinical usage for the first time in the Russian Federation, it was based of NATION epidemiologic study database (more than 26 000 participants). The following mathematical instruments have been used: mathematic modelling, main components methodology, binary variables, correlation analysis and single-factor analysis of variance.RESULTS: Highest coefficients of logistic regression for PreD (p<0.05) were identified for age — ≥52 years old for women and ≥59 years old for men (1,48); body mass index ≥31 (0.75); waist circumference ≥100 сm for women and ≥112 cm for men (0.90). In the same time coefficients for DM2T were for for age — ≥52 years old for women and ≥59 years old for men (1,24); body mass index ≥31 (1,19), high blood fasting glucose analysis in the past (1,37); waist circumference / hip circumference ratio ≥0.85 for women and ≥0.92 for men (1,05), high blood pressure (0.69). Correlation coefficients were taken into account and score has been used for specialized questionnaire creation. Sensitivity and specificity for PreD were 83,8% and 59,3% accordingly, for DM2T — 85,4% and 73,6% accordingly. DM2T may be suspected when total score of questionnaire is 11 and higher, and PreD — when total score will be ≥7 and <11.CONCLUSIONS: The calculator based on questionnaire (DIARISK) allows to separate of potential patient for PreD and DM2T confirmation during first examination or dispanserization. A patent for innovation has been issued

Perfect Absorption of a Focused Light Beam by a Single Nanoparticle

Absorption of electromagnetic energy by a dissipative material is one of the most fundamental electromagnetic processes that underlies a plethora of applied problems, including sensing, radar detection, wireless power transfer, and photovoltaics. Common wisdom is that a finite dissipative object illuminated by a plane wave removes only a finite amount of the wave\u27s energy flux, which is determined by the object\u27s absorption cross-section. Thus, it is of fundamental interest to see if any far-field waveform can be perfectly absorbed by a finite object. Here, it is theoretically demonstrated that a precisely tailored light beam containing only far-field components can be perfectly absorbed by a finite scatterer on a substrate. The self-consistent scattering problem in the dipole approximation is analytically solved and finds a closed-form expression for the spatial spectrum of the incident field and the required complex polarizability of the particle. All analytical predictions are confirmed with full-wave simulations. The results introduce a qualitatively novel class of perfect absorption phenomena in electromagnetics and other wave processes

Analytical Calculations of Scattering Amplitude of Surface Plasmon Polaritons Excited by a Spherical Nanoantenna

Since surface plasmon polaritons (SPPs) are surface waves, they cannot be excited by an incident plane wave, because free-space photons do not possess a sufficient in-plane momentum. Phase matching between the incident light and SPP can be achieved using a high-refractive-index prism, grating, or nanoantennas. In this work, we found an expression for the amplitude of SPP excited by an arbitrary 3D current distribution placed near a metal interface. The developed method is based on the well-known technique used in waveguide theory that enables finding the amplitudes of waveguide modes excited by the external currents. It reduces the SPP excitation problem to the summation of the set of emitters. As a particular example, we considered a spherical dipole nanoantenna on a metal substrate illuminated by a normally incident plane wave. The analytical calculations were in good agreement with the full-wave numerical simulations

Optomechanical Manipulation With Hyperbolic Metasurfaces

Auxiliary nanostructures introduce additional flexibility into optomechanical manipulation schemes. Metamaterials and metasurfaces capable to control electromagnetic interactions at the near-field regions are especially beneficial for achieving improved spatial localization of particles, reducing laser powers required for trapping, and for tailoring directivity of optical forces. Here, optical forces acting on small particles situated next to anisotropic substrates, are investigated. A special class of hyperbolic metasurfaces is considered in details and is shown to be beneficial for achieving strong optical pulling forces in a broad spectral range. Spectral decomposition of Green\u27s functions enables identifying contributions of different interaction channels and underlines the importance of the hyperbolic dispersion regime, which plays the key role in optomechanical interactions. Homogenized model of the hyperbolic metasurface is compared to its metal-dielectric multilayer realizations and is shown to predict the optomechanical behavior under certain conditions related to composition of the top layer of the structure and its periodicity. Optomechanical metasurfaces open a venue for future fundamental investigations and a range of practical applications, where accurate control over mechanical motion of small objects is required

Fast Simulation of Light Scattering and Harmonic Generation in Axially Symmetric Structures in COMSOL

The study of electromagnetic scattering in optics and nanophotonics is crucial for understanding complex nanostructures and optical devices. However, numerical analysis of scattering spectra, even for simple shape nanocavities, presents significant computational challenges. This paper focuses on simplifying the simulation process by utilizing system symmetries and the separation of variables, which reduces the dimension of the problem. Specifically, we present a practical guide to efficiently simulate linear and nonlinear scattering problems in COMSOL Multiphysics for axisymmetric objects. This includes computing the scattering cross-section, multipolar decomposition, optical forces, and second harmonic generation (SHG). We show that by reducing the calculation time we are able to analyze the generation spectra of SH under varying geometrical parameters of nanoantennas across a broad range. Additionally, we study the increase in SHG within a high-Q state at the band edge in a chain of dielectric discs with lengths ranging from 5 to 20 particles. We also accompany the provided guide with the ready-to-run COMSOL models