Design and Optimization of Nanoantennas for Nano-Optical Applications

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2020-9

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Işıklar, Göktuğ

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In this study, design and simulation of plasmonic nanoantenna structures to obtain high power enhancement capabilities at optical frequencies, as well as utilization of nanoantennas for imaging and sensing applications are presented. Plasmonic characteristics of nanoantennas, which depend on many parameters, such as material, frequency, geometry, and size, are investigated in detail via computational analyses of various nanoantenna structures. Numerical solutions of electromagnetic problems are performed by using surface-integral-equation formulations that are suitable for plasmonic objects, while the simulations are accelerated, where necessary, by employing the multilevel fast multipole algorithm. Various nanoantenna designs, including slitted structures and novel geometries obtained via shape optimization, are studied and compared with each other and with examples from the literature. Numerical analyses demonstrate superior properties of different nanoantenna designs depending on the frequency. In order to exemplify the applications that nanoantennas can be used for practical purposes, plasmonics structures with high optical sensitivities are designed by using bowtie geometries for particle sensing and nano-optical imaging applications. In this context, computational analyses of detection of nanoparticles with different shapes, sizes, and electrical properties are presented. Numerical results demonstrate the feasibility of particle detection and identification with both nanoantenna arrays and improved nano-holes.

Subject Keywords

Genetic Algorithms, Multilevel Fast Multipole Algorithm, Method of Moments, Electromagnetic Scattering, Nano-Optical Imaging, Nano-Optical Sensors, Nanoantennas, Plasmonics

URI

https://hdl.handle.net/11511/69210

Collections

Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

G. Işıklar, “Design and Optimization of Nanoantennas for Nano-Optical Applications,” M.S. - Master of Science, Middle East Technical University, 2020.