Improved Nano-optical Traps for Single-particle Sensing Applications

2019-01-01
Isiklar, G.
Algun, M.
Ergül, Özgür Salih
We present numerical design and simulations of nano-optical traps for single-particle sensing applications. While commonly used nano-holes with circular shapes are suitable for physically trapping nanoparticles to be detected and identified, they generate relatively weak signals in the far zone, especially when nanoparticles are small. We show that optical sensitivity of nano-holes can be enhanced significantly by using well-designed tip geometries such that metallic and dielectric nanoparticles can be detected and identified based on far-zone scattering data. Numerical simulations are performed to test the designed nano-holes and demonstrate their excellent performances in various scenarios.

Suggestions

Optimal Cavities to Enhance Free-space Matching in Solar Cells
Karaosmanoglu, B.; Topcuoglu, U.; Guler, S.; Tuygar, E.; Ergül, Özgür Salih (2018-08-04)
In this paper, we present design and numerical simulations of nano-cavities for free space matching in solar cells at optical frequencies. The cavity designs are inspired by the wellknown antenna geometries that are commonly used at radio and microwave frequencies. Using such designs that have not been explored before in the context of solar cells, the electromagnetic mismatch between solar-cell surfaces and vacuum is significantly reduced, in comparison to planar interfaces and those with the conventional ...
Accurate analysis of metamaterials involving finite arrays of split-ring resonators and thin wires
Gurel, Levent; Ergül, Özgür Salih; Unal, Alper (2007-03-30)
In order to gain physical insight into how some metamaterial structures behave, we report our results obtained by accurate numerical solutions of electromagnetic problems related to various constructions of split-ring-resonators (SRRs) and thin wires (TWs). Single and multiple layers of arrays of SRRs and TWs are investigated in detail using the electric-field integral equation. Without utilizing any homogenization techniques, we accurately model large numbers of unit cells that translate into very large co...
Efficient and Accurate Electromagnetic Optimizations Based on Approximate Forms of the Multilevel Fast Multipole Algorithm
Onol, Can; Karaosmanoglu, Bariscan; Ergül, Özgür Salih (2016-01-01)
We present electromagnetic optimizations by heuristic algorithms supported by approximate forms of the multilevel fast multipole algorithm (MLFMA). Optimizations of complex structures, such as antennas, are performed by considering each trial as an electromagnetic problem that can be analyzed via MLFMA and its approximate forms. A dynamic accuracy control is utilized in order to increase the efficiency of optimizations. Specifically, in the proposed scheme, the accuracy is used as a parameter of the optimiz...
Rigorous Analysis of Deformed Nanowires Using the Multilevel Fast Multipole Algorithm
Karaosmanoglu, Bariscan; Yilmaz, Akif; Ergül, Özgür Salih (2015-05-17)
We present accurate full-wave analysis of deformed nanowires using a rigorous simulation environment based on the multilevel fast multipole algorithm. Single nanowires as well as their arrays are deformed randomly in order to understand the effects of deformations to scattering characteristics of these structures. Results of hundreds of simulations are considered for statistically meaningful analysis of deformation effects. We show that deformations significantly enhance the forward-scattering abilities of ...
Accurate solutions of scattering problems involving low-contrast dielectric objects with surface integral equations
Ergül, Özgür Salih (2007-11-16)
We present the stabilization of the surface integral equationsfor accurate solutions of scattering problems involvinglow-contrast dielectric objects. Unlike volume formulations,conventional surface formulations fail to provide accurateresults for the scatteredfields when the contrast of theobject is small. Therefore, surface formulations are requiredto be stabilized by extracting the nonradiating parts of theequivalent currents. In addition to previous strategies forthe stabilization, we introduce a n...
Citation Formats
G. Isiklar, M. Algun, and Ö. S. Ergül, “Improved Nano-optical Traps for Single-particle Sensing Applications,” 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57924.