ABSTRACT
A high-efficiency subwavelength diffractive beam combiner operating in a visible spectral range is designed, fabricated, and demonstrated. Such a device combines red, green, and blue color beams into one output light beam. Diffraction efficiencies of different types of gratings are calculated for various materials, incidence angles, and polarizations of light. It is shown that the plasmon resonance via a grating coupling occurs at the determined conditions. Subwavelength gratings with a period of 400 nm are fabricated and tested using laser and laser diode sources.
ABSTRACT
We have synthesised some of 2-substituted 4-(3H)-quinazolones by the reaction with benzaldehyde and cinnamic aldehyde and their derivatives. It is shown that the intensity of the reaction depends on electrophilic properties of carbonyl compounds and steric factors. The elemental analysis, ultraviolet (UV), infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of synthesised compounds, their individuality being checked by thin-layer chromatography. The results of biological experiments show that the synthesised 2-substituted 4-(3H)-quinazolones have an expressed antioxidant and antiamnestic activity and are prospective for further research of their nootropic activity.
