Low-cost and easily replicable apparatus: an Arduino controlled device for educational activities focused on measuring Brewster’s angle

In this work, we report the development of a low-cost Arduino-controlled device for didactic activities in light polarization. The main body of the prototype was designed and produced using laser-cut medium density fibreboard parts, including gears and pulleys. As a light source and detector, a 532 nm laser pointer and a light dependent resistor were used, respectively. The moving parts (light source and detector) are controlled using a stepper motor (28BYJ-48) with the ULN2003 driver. The apparatus was tested with glass and plastic (polystyrene) slides. The results show that the prototype can distinguish between parallel and perpendicular polarization (to the plane of incidence). In addition, it is demonstrated that the prototype can be satisfactorily applied to determine the Brewster’s angle, even for solids with close refractive indexes.

Optical Properties from a Single GaAs Quantum Dot Structure

We observed exciton and biexciton states in a single GaAs quantum dot at 4 K using micro pho-toluminescence system and investigated power dependent photoluminescence measurements to identify both exciton and biexciton states. The biexciton and exciton states showed quadratic (a~2.2) and linear (a~0.95) increasing power factor, respectively. The large energy difference (~0.2 meV) from exciton states for the perpendicular polarization was observed.

Запись поляризационных голограмм в пленках сополимеров 4-((2-бром-4-нитрофенил)диазенил)фенилметакрилата

Recording media for polarization holography have been created on the basis of 4-((2-bromo-4-nitrophenyl)diazenyl)phenyl methacrylate copolymers, and the properties during that they manifest during recording of holograms of a plane wavefront have been studied. It has been found that the hologram recording rate at room temperature is the same for the perpendicular and parallel polarization of recording rays and the hologram relaxation rate is higher in the case of perpendicular polarization orientation of recording rays. It has been shown that the diffraction efficiency of holograms does not exhibit a monotonic relation with the film softening temperature.

A Multibeam Dual-Band Orthogonal Linearly Polarized Antenna Array for Satellite Communication on the Move

The design and simulation of a 10 × 8 multibeam dual-band orthogonal linearly polarized antenna array operating at Ku-band are presented for transmit-receive applications. By using patches with different coupling methods as elements, both perpendicular polarization in 12.25–12.75 GHz band and horizontal polarization in 14.0–14.5 GHz band are realized in a shared antenna aperture. A microstrip Rotman lens is employed as the beamforming network with 7 input ports, which can generate a corresponding number of beams to cover −30°–30° with 5 dB beamwidth along one dimension. This type of multibeam orthogonal linearly polarized planar antenna is a good candidate for satellite communication (SatCom).

A COMPARATIVE STUDY OF OPTICAL PROPERTIES OF C3N AND CN3 SYSTEMS THROUGH DENSITY FUNCTIONAL THEORY (DFT)

The optical properties of (8,0) single wall carbon nanotubes (SWCNTs) alloyed with nitrogen ( N ) are computed using ab initio density functional theory (DFT). Both the real as well as imaginary dielectric constant in the long wavelength limit depends essentially on the nature of electromagnetic field. It is observed that for CN 3 systems, the reflectivity vanishes at 3.45, 6.95, and 8.20 eV, respectively for parallel, perpendicular polarization, and unpolarized light with incidence (1,0,0), while for C 3 N the vanishing reflectivity occurs only for parallel polarization at 8.05 eV. Although the magnitude of the significant peaks of loss function of CN 3 systems are comparable to C 3 N in perpendicular and unpolarized situation, however, they are significantly one order of magnitude higher in CN 3 for parallel polarization.