The doctoral dissertation in the field of Physics will be examined at the Faculty of Science, Forestry and Technology, Joensuu campus.
What is the topic of your doctoral research? Why is it important to study the topic?
MSc Anar Ospanova’s doctoral research is dedicated to the study of transparency and invisibility problems in subwavelength particles and metamaterials. Metamaterials are widely known as surfaces comprising ordered inclusions to control electromagnetic waves for the tasks of localization, enhancing, filtering, and modulating electromagnetic fields for further applications. We attempt to provide a comprehensive tool for correct understanding of resonant behaviour in planar metamaterials by expanding near-fields in charge-current units. Thus, we develop so called secondary multipole expansion method for accurate classification of effects of invisibility and transparency due to straight computation on the base of occurring charges and currents.
What are the key findings or observations of your doctoral research?
In the frame of doctoral research there was established the method of secondary multipole expansion for investigation of resonant behaviour in planar metamaterials. The novelty of this method is on the considering of geometrical center of the source that is usually neglected. Here we also have presented the planar metamaterial exhibiting broadband transparency in the wide range, which was correctly explained in the frame of proposed theory. We also have presented high-efficiently bound-state-in the continuum effect occurring in planar metamaterial that was correctly explained in the frame of proposed theory. These finding was successfully confirmed experimentally and may find application in different fields.
How can the results of your doctoral research be utilised in practice?
Proposed model of spheroidal particle is capable to bend the incident wave to the lateral radiation, thus eliminate forward and backward scattering. That way, it can be of great practical interest in light manipulation problems. Proposed planar metamaterial has demonstrated broadband transparency in Gigahertz frequency range. This feature can be widely utilized in data transfer and sensing problems. Proposed planar metamaterial for demonstration of the bound state in the continuum effect can be demanded in that field where signal amplification is required.
What are the key research methods and materials used in your doctoral research?
Ospanova’s doctoral research is mainly focused in theoretical investigation of electrodynamical effects in metamaterials, that is mainly theoretical methods and computational tools were exploited. All used methods have shown accuracy in previous studies. As for practical implementation, conventional laser cutting was exploited. Measurement was carried out using Vector Network Analyzing tool.
The doctoral dissertation of Anar Ospanova, MSc, entitled Multipole approach in the invisibility and transparency problems will be examined at the Faculty of Science, Forestry and Technology, Joensuu Campus. The opponent will be Professor Ildiko Peter, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, Romania, and the custos will be Professor Jyrki Saarinen, University of Eastern Finland. Language of the public defence is English.
