الفهرس 
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Abstract
The goal of antenna design at optical frequencies is to deliver optical electromagnetic energy to loads in the form of, e.g., atoms, molecules or nanostructures, or to enhance the radiative emission from such structures, or both.
The research problem: The mismatch between the dimensions of nanoscale devices and the length scale associated with optical wavelengths (diffraction limit). Confinement of optical radiation in a subwavelength region (optical spots in a nano-dimensions) is required for various applications such as near-field sample detection, optical microscopy, optical sources, optical detectors and optical networks, Nanomanufacturing, Nanoimaging, Cancer treatment, DNA analyzes, New probes for biology, Solar energy and etc.
Aim of the study: Modeling the optical antennas and evaluate the performance of these devices for choosing the best suited antenna geometry for a given application.
Study Procedure: The optical properties of plasmonic nanoantennas are investigated in details using the finite integration technique (FIT) and discrete dipole approximation (DDA). The validity of these numerical techniques are verified by comparison to the exact solution generalized Mie method (GMM). The influence of the geometrical parameters (antenna length, gap dimension and shapes) on the antenna field enhancement and spectral response is discussed.
Thesis conclusions: The strongest field enhancement occurs for particles with sharp tips (e.g. triangular prisms, pyramids). The enhanced field is equivalent to a strong light spot which can lead to the resolution improvement of the microscopy and optical lithography, thus increasing the optical data storage capacity.