Design and simulation of nana-optical beam generators based on zero-index materials

2019-09-01
Eris, Ozgur
Abanuzoglu, Tutku
Ergül, Özgür Salih
We present design and computational analysis of near-zero-index (NZI) structures that act as nano-optical beam generators when excited internally by isotropic sources. The designed structures have homogenized shell geometries with various modifications to generate asymmetric tridirectional, bidirectional, and unidirectional beams, in addition to symmetric ones. NZI properties make it possible to generate beams from planar surfaces, while numerical results show that the behavior of a shell is very sensitive to the geometric parameters and the nature of the NZI, i.e., permittivity and permeability values. We show that, by using asymmetric cavities and pyramidal textures, it is possible to generate asymmetric beams with suitable choices of dimensions and material properties.
2019 Fifth International Electromagnetic Compatibility Conference (EMC Turkiye)

Suggestions

Numerical Investigation of Nano-Cavities for Optimal Power Absorption in Solar Cells
Karaosmanoglu, Bariscan; Topcuoglu, Ulas; Tuygar, Emre; Ergül, Özgür Salih (2018-06-01)
We present a numerical study of nano-cavities used in solar cells for energy harvesting, by employing surface integral equations based on Maxwell's equations in the frequency domain and an efficient solver based on the multilevel fast multipole algorithm (MLFMA). With the three-dimensional modeling of surfaces, we obtain accurate results to evaluate the performances of different structures for improved power absorption in solar cells. This paper includes a brief description of the developed solver and initi...
Design and performance analysis of a pump-turbine system using computational fluid dynamics
Yıldız, Mehmet; Albayrak, Kahraman; Çelebioğlu, Kutay; Department of Mechanical Engineering (2011)
In this thesis, a parametric methodology is investigated to design a Pump-Turbine system using Computational Fluid Dynamics ( CFD ). The parts of Pump-Turbine are created parametrically according to the experience curves and theoretical design methods. Then, these parts are modified to obtain 500 kW turbine working as a pump with 28.15 meters head. The final design of Pump-Turbine parts are obtained by adjusting parameters according to the results of the CFD simulations. The designed parts of the Pump-Turbi...
Design and Testing of a Linear Generator for Wave-Energy Applications
Hodgins, Neil; Keysan, Ozan; McDonald, Alasdair S.; Mueller, Markus A. (2012-05-01)
A linear-generator topology is proposed for wave-energy applications. The main significance of the generator topology is that the relative position of the magnets, copper, and steels has been chosen so that there are no magnetic attraction forces between a stator and a permanent-magnet (PM) translator. The lack of magnetic forces and the modular nature of the generator topology make the manufacture and assembly of the generator easier than a conventional iron-cored PM linear generator. Analytical modeling t...
Analysis of double-negative materials with surface integral equations and the multilevel fast multipole algorithm
Ergül, Özgür Salih (2011-08-13)
We present a fast and accurate analysis of double-negative materials (DNMs) with surface integral equations and the multilevel fast multipole algorithm (MLFMA). DNMs are commonly used as simplified models of metamaterials at resonance frequencies and are suitable to be formulated with surface integral equations. However, realistic metamaterials and their models are usually very large with respect to wavelength and their accurate solutions require fast algorithms, such as MLFMA. We consider iterative solutio...
Computational analysis and full-wave optimizations of nanoantenna arrays for desired scattering and radiation characteristics
Altmoklu, Askin; Ergül, Özgür Salih (2017-08-26)
We present computationally intensive analysis and optimizations of nanoantenna arrays made of dielectric or metallic elements. Scattering and radiation characteristics of the arrays are obtained by using surface integral equations that can be used for penetrable objects, including plasmonic structures. Optimizations are performed via genetic algorithms, while the required thousands of trials are performed efficiently by using the multilevel fast multipole algorithm. Numerical results involving arrays of nan...
Citation Formats
O. Eris, T. Abanuzoglu, and Ö. S. Ergül, “Design and simulation of nana-optical beam generators based on zero-index materials,” presented at the 2019 Fifth International Electromagnetic Compatibility Conference (EMC Turkiye), Kocaeli, Turkey, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52459.