High Q-factor Fabry-Perot Microresonator as an Alternative to Microdisk in Electro-Optical Modulator for Microwave-Photonic Receivers, Journal of Telecommunications and Information Technology, 2013, nr 2

In the last decade a new idea has been suggested for receivers of communication systems, namely, in microwave receivers’ architecture. Though superheterodyne radio-frequency receivers are best suited to the needs of contemporary wireless communication, however stray radiation of their local oscillator (heterodyne) interferes with neighboring radio-devices and permits to locate the covert receiver. To overcome this drawback the signal transfer to optical range has been suggested. By this conversion, not only an elimination of receiver’s stray radiation is attained but also vast advantages of photonic signal processing become available. The key element of existing microwave-photonic receivers is electro-optical microdisk modulator. However, its realization is complicated and as an alternative an electro-optical modulator based on high Q-factor Fabry-Perot microresonator is suggested. Comparative analysis of both types of modulators is performed, and advantages of high Q-factor Fabry-Perot microresonator based modulator are highlighted

Enhancement of Air-groundMatching by Means of a Chirped MultilayerStructure: Electromagnetic Modelingwith the Method of Single Expression, Journal of Telecommunications and Information Technology, 2017, nr 3

The enhancement of air-ground electromagneticmatching by means of a chirped multilayer structure is inves-tigated. The modeling and simulation of the considered struc-ture are performed by using the method of single expression(MSE), which is a convenient and accurate tool for wavelength-scale simulations of multilayers comprising lossy, amplifyingor nonlinear (Kerr-type) materials. Numerical results showthat a suitable chirped multilayer structure can reduce the re- ection from the ground. Different values of the number oflayers and of the layer thicknesses are considered. The distributions of the electric eld components and the power owdensity within the modelled structures are calculated

Influence of Chirped DBR Reflector on the Absorption Efficiency of Multi-nanolayer Photovoltaic Structures: Wavelength-scale Analysis by the Method of Single Expression, Journal of Telecommunications and Information Technology, 2017, nr 3

An electromagnetic wavelength-scale analysis of the optical characteristics of multi-nanolayer photovoltaic (PV) structures: without an antireflection coating, with an antireflection coating on the top of the structure, and with both the antireflection coating on the top and a broadband non-periodic (chirped) distributed Bragg reflector (DBR) on the bottom of the structure is performed. All the PV structures studied are based on a Si p-i-n type absorber supported by a metallic layer (Cu) and SiO2 substrate. The top-to-bottom electromagnetic analysis is performed numerically by the method of single expression (MSE). Absorbing and reflecting characteristics of the multi-nanolayer PV structures are obtained. The influence of the thicknesses and permittivities of the layers of the PV structures on the absorbing characteristics of the structures is analyzed to reveal favourable configurations for enhancement of their absorption efficiency. The localizations of the electric component of the optical field and the power flow distribution within all the PV structures considered are obtained to confirm an enhancement of the absorption efficiency in the favorable configuration. The results of the electromagnetic wavelength-scale analysis undertaken will have scientific and practical importance for optimizing the operation of thin-filmmulti-nanolayer PV structures incorporating a chirped DBR reflector with regards to enhancing their efficiency

Foreword to the Special Issue

We are very pleased to present the Special Issue “Recent Progress in Electromagnetic Theory and its Applications”, an outcome of the COST (European Cooperation in Science and Technology) Action TU1208 “Civil engineering applications of Ground Penetrating Radar”. The Special Issue comprises two parts: Part I includes eight papers on Ground Penetrating Radar (GPR) technology, methodology and applications; Part II contains six papers dealing with other applications of electromagnetic fields. Overall, the papers are authored by scientists from nineteen institutes in nine countries (Armenia, France, Germany, India, Ireland, Italy, Poland, Russia, and United Kingdom)

Enhancement of Air-ground Matching by Means of a Chirped Multilayer Structure: Electromagnetic Modeling with the Method of Single Expression

The enhancement of air-ground electromagnetic matching by means of a chirped multilayer structure is inves- tigated. The modeling and simulation of the considered struc- ture are performed by using the method of single expression (MSE), which is a convenient and accurate tool for wavelength- scale simulations of multilayers comprising lossy, amplifying or nonlinear (Kerr-type) materials. Numerical results show that a suitable chirped multilayer structure can reduce the re- flection from the ground. Different values of the number of layers and of the layer thicknesses are considered. The dis- tributions of the electric field components and the power flow density within the modelled structures are calculated

Comparative Modeling of Infrared Fiber Lasers

The modeling and design of fiber lasers facilitate the process of their practical realization. Of particular interest during the last few years is the development of lanthanide ion-doped fiber lasers that operate at wavelengths exceeding 2000 nm. There are two main host glass materials considered for this purpose, namely fluoride and chalcogenide glasses. Therefore, this study concerned comparative modeling of fiber lasers operating within the infrared wavelength region beyond 2000 nm. In particular, the convergence properties of selected algorithms, implemented within various software environments, were studied with a specific focus on the central processing unit (CPU) time and calculation residual. Two representative fiber laser cavities were considered: One was based on a chalcogenide–selenide glass step-index fiber doped with trivalent dysprosium ions, whereas the other was a fluoride step-index fiber doped with trivalent erbium ions. The practical calculation accuracy was also assessed by comparing directly the results obtained from the different models