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[Regional keeping track of regarding microbe infections by using standardized situation fatality costs while using example of SARS-CoV-2 inside Bavaria].
We use this model to discuss the suitability of several commercial spectrophotometers to accurately measure the translucent materials of various optical properties and show that not all devices can adapt to all translucent materials.We demonstrated a compact optical module that is capable of efficiently generating vector vortex beams (VVB). With this device, a linearly polarized input beam can be converted into a vector beam with arbitrary spatial polarization and phase distributions, accompanied by an energy utilization up to 61%. Equally important, the area utilization of the spatial light modulator, a key component in the device, is as high as 65.5%. With the designed vector-vortex-beam-generation module, several types of VVBs with different vortex topological charges and spatial polarization distributions were created experimentally. This device may find applications in optical tweezers, laser machining, and so on.Solid core circular and octagonal photonic crystal fibers (CPCF and OPCF) are proposed for analyzing different guiding properties such as dispersion, effective mode area, nonlinearity, and confinement loss from 0.8 to 2.6 µm wavelength. The proposed structures use three different types of background materials SF10, BK7, and silica. Moreover, the fill fraction is varied by changing the diameter of the air hole where the lattice pitch is unchanged. The proposed PCFs show a high negative dispersion with low confinement loss and small effective mode area. OD36 In the proposed design, the finite element method with a perfectly matched layer absorbing boundary condition is used. At 1.8 µm wavelength with 0.6 fill fraction, the maximum negative dispersion of -922.5ps/(nm.km) is observed for CPCF when the background material is SF10. In addition, at this particular wavelength, the confinement loss is observed to be very small. Moreover, -560.12ps/(nm.km) dispersion is found for the similar condition at 1.55 µm wavelength. On the other hand, using BK7 as the background material, -706.77ps/(nm.km) dispersion is found at 1.55 µm wavelength for CPCF. Results also imply that CPCF shows better performance than OPCF for a wide wavelength range. Furthermore, at 1.55 µm wavelength, silica-based glass exhibits maximum dispersion, whereas increasing wavelength flint type glass shows the similar result. Analyzing different guiding properties of PCFs has significant impact on broadband dispersion compensation applications, especially using SF10.An experimental method is developed for robust frequency stabilization using a high-finesse cavity when the laser exhibits large intermittent frequency jumps. This is accomplished by applying an additional slow feedback signal from Doppler-free fluorescence spectroscopy in an atomic beam with increased frequency locking range. As a result, a stable and narrow-linewidth 556 nm laser maintains the frequency lock status for more than a week and contributes to more accurate evaluation of the Yb optical lattice clock. In addition, the reference optical cavity is supported at vibration-insensitive points without any vibration isolation table, making the laser setup more simple and compact.In this paper, a thin film constructed by a periodic assembly of graphene-wrapped particles with spherical geometry has been proposed as a polarization-insensitive reconfigurable perfect absorber. The performance of the proposed structure is based on the cooperative excitation of the quadrupole localized surface plasmons on graphene shells. By sweeping the quality of graphene shells, it is recognized that the low-quality graphene material is the best choice for the absorber design. Moreover, the effect of graphene chemical potential and periodicity of the particles on the absorptivity of the structure is investigated. The physical mechanism of performance is clarified by investigating the excited localized surface plasmon resonances. In addition, the angle-independent behavior up to around 60 degrees for both transverse electric (TE) and transverse magnetic (TM) waves is proved. Interestingly, by engineering the substrate height, our proposed absorber exhibits dynamic broadband performance due to the impedance matching and multiband absorption by enhancing the Fabry-Perot resonances of a micrometer-sized substrate. The possibility of attaining a similar static broadband response by stacking multiple layers is also proved. Our proposed sub-wavelength absorber can be suitable for novel optoelectronic devices due to its simple geometry.Focused laser differential interferometry (FLDI) is used to measure a well-characterized, 17 kHz screech tone emitted from an underexpanded Mach 1.5 jet. Measurements are made at numerous spatial locations in and around the jet flow-field, where intrusive diagnostics would otherwise influence the flow-field. Results from FLDI measurements are shown to agree with measurements from microphones and analyses of high-speed schlieren. The agreement is used to demonstrate FLDI is a valid and accurate technique for measuring screech tones in jet flow-fields, and furthermore that FLDI can be used to measure jet screech at various spatial locations around the jet, and notably inside of the jet, where microphones and other intrusive diagnostics cannot be used effectively.A novel machine learning (ML) clustering algorithm, named light-fidelity (LiFi) Grid, is proposed to design amorphous cells of LiFi access points (APs) in order to maximize the minimum signal-to-interference-plus-noise ratio (SINR) from the viewpoint of user-centric (UC) network design. The algorithm consists of two phases. Explicitly, the first phase consists of finding clusters of user densities based on the mean-shift (MS) clustering algorithm. In contrast to some other clustering algorithms, such as K-means, MS does not need to know the number of clusters in advance. Furthermore, the combined transmission scheme is assumed in each cell. In the second phase, this paper proposes a novel clustering algorithm that addresses the problem of grouping APs based on the positions of users-UC design-in optical wireless networks (OWNs). Hence, it addresses the dynamic resource allocation problem in OWNs if APs are considered as network resources. Based on the maximization of minimum SINR metric, LiFi Grid demonstrates the superior performance relative to conventional fixed-shape cell-centric network designs.
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