Energy Yield of Multijunction Solar Cells With Allowance for the Latitude Variability of the Spectral Composition Radiation DOI: 10.22184/1993-7296.FRos.2023.17.7.516.524
Ioffe Physical-Technical Institute of the Russian Academy of Sciences, Saint-Petersburg, Russia
An energy yield assessment of the multijunction solar cells is proposed with allowance for the total spectral composition of direct solar radiation during the annual period. It is shown that the energy yield ratio of a four-junction solar cell near the equator is 45% in the case of an atmosphere with a low aerosol composition and 44% in the case of an atmosphere with an aerosol filling typical for the urban areas. At a latitude of +30°, the annual energy yield of this solar cell can be 1001 kWh/m2. To calculate the energy yield of installations and photovoltaic modules with such solar cells, this value adjustment is required due to the energy losses caused by the power plant design.
Axially Symmetric Hermite-Gaussian Beams and the BB84 Protocol for the Space-Earth Quantum Cryptography Channel DOI: 10.22184/1993-7296.FRos.2023.17.7.542.555
The paper provides a description of Hermite-Gaussian beams with an axially symmetric polarization structure generated by a vector superposition of Hermite-Gaussian modes with the indices 10 and 01. It is shown that the axial polarization symmetry makes such beams insensitive to the rotations relative to the optical axis that makes such a modification of the well-known BB84 protocol preferred for the quantum space cryptography systems. The possible creation and detection of such beams within the framework of a polarization protocol transmission using the devices with a radial polarizer is discussed.
Study of Integrated Optical Switch for Development of Logical Element Controlled by the Thermal Influence on Ge2Sb2Te5 Layer (GST) DOI: 10.22184/1993-7296.FRos.2023.17.7.556.564
The alternating phase layer Ge2Sb2Te5 (GST) demonstrates a significant refractive index difference between the amorphous (a-GST) and crystalline (c-GST) states. The fast and reversible phase transition between the two states allows for high speed and thermal stability of integrated optical devices. The paper presents a study of an integrated optical switch based on an annular microresonator with a superimposed GST layer controlled by the thermal influence. Such switches may be used in the optical circuits to implement logic functions.
Study of the Systems for Laser Diode Radiation Output Into a Single-Mode Optical Fiber DOI: 10.22184/1993-7296.FRos.2023.17.7.526.538
An optical radiation output system of a laser diode based on a discrete ball lens and a fiber ball lens is proposed. The sensitivity of the following optical radiation output systems of a laser diode to the deviation of elements from the optimal position is determined: laser diode – cleaved optical fiber, laser diode – tapered optical fiber, laser diode – discrete molded lens – cleaved optical fiber, laser diode – discrete ball lens – fiber ball lens. The recommendations are given for the use of these systems in packaging the microwave-photonic modules including the photonic integrated circuits produced with an InP technology.
Assessment Procedure for the Advantages of LED Phyto-Strip Application in the Industrial Greenhouse Complexes DOI: 10.22184/1993-7296.FRos.2023.17.7.566.578
The efficiency of LED phyto-strip in the field of photosynthetically active radiation has been assessed and compared with the alternative phyto-irradiators used in the industrial greenhouse complexes. The phyto-strip efficiency in the field of photosynthetically active radiation was equal to 42% that was 4.7 times higher than the efficiency of a full-spectrum grow lamp and 4.4 times higher than the efficiency of a fluorescent lamp. The spectral and energy characteristics of the LED phyto-strip have been determined. The average value of the photosynthetic photon flux density applicable for the plant growing process (≈300 µmol / m2 / s) is achieved when radiation is obtained from one meter of phyto-strip at a distance of ≈20 cm from the irradiated area when current is passed through it. Due to its high efficiency, the phyto-strip will improve the growth results of various crops in the autonomous agro-industrial enterprises, and will also reduce the energy costs.
Luminescence Nanothermometry by Single Organic Molecules: Manifestation of Electron-Phonon Interaction DOI: 10.22184/1993-7296.FRos.2023.17.7.508.514
Luminescent thermometry is a rapidly growing scientific method based on the dependence of the luminescent and spectral characteristics of nano-sized emitters on temperature. The accuracy of this method depends significantly on the theoretical models used to describe the temperature behavior of the spectra. In this paper, we provide a brief overview of our recent results related to new approaches to interpreting the temperature broadening of the spectral lines of single organic molecules in a polymer matrix as a result of electron-phonon interaction. We believe that the approach under consideration can be successfully applied to a variety of promising emitters used in luminescent thermometry.