A hyperspectrometer based on the Offner scheme was investigated. Spectral characteristics were studied and calibrated using a standard spectrometer. As a result of estimating the deviations of the spectra of the imaging hyperspectrometer and the reference spectrometer, calibration coefficients were obtained. The reflectance spectra of beets, onions and potatoes under natural solar illumination were experimentally obtained. Based on the analysis of hyperspectral imaging data, an analysis of the distribution of vegetative indices and, in particular, moisture content, was carried out. Analysis of histograms of moisture content index distribution was carried out.
In the present work, on-chip dielectric diffraction gratings for steering the propagation of surface plasmon polaritons (SPP) are theoretically, numerically and experimentally studied. The investigated plasmonic gratings consist of dielectric ridges located on the SPP propagation surface (on the metal surface). In contrast to Bragg gratings, at normal incidence the periodicity direction of the grating is perpendicular to the SPP propagation direction. The studied gratings are designed using a simple plane-wave grating model and rigorously simulated using the aperiodic Fourier modal method for numerical solution of Maxwell’s equations. In particular, plasmonic grating-based beam splitter with subwavelength footprint in the propagation direction is presented. Along with the theoretical and numerical results, proof-of-concept experimental results are presented. The investigated grating-based plasmonic gratings were fabricated from resist on a silver film using electron beam lithography and characterized using the leakage radiation microscopy technique. The obtained experimental results are in good agreement with the performed numerical simulations. The proposed on-chip gratings may find application in the design of systems for optical information transmission and processing at the nanoscale.
Experimental research in deposition of thin CdTe films was carried out using the resistive dynamic vacuum evaporation method. While forming thin CdTe films, temperature parameters of a substrate varied. Parameters of obtained CdTe films were investigated using Raman spectroscopy, scanning profilometry and scanning electron microscopy. The measured results showed high quality of thin CdTe films deposited on the substrate at temperature of 300°C and 450°C.
In this paper we provide 3d full-vector static electromagnetic simulation of silicon micro-ring resonator operating. We show that geometrical and scalar approaches are not sufficiently accurate for calculating resonator parameters. Quite strong dependence of ring resonator radius on waveguide width is revealed.