Showing 4 results for Modes
Rana Asgari Sabet, Habib Khoshsima,
Volume 13, Issue 1 (1-2019)
Abstract
In this paper, we perform a detailed study of the spectral response of the gold U-shaped nano-structures for different geometrical parameters and polarizations in order to obtain significant localization factor in the wavelength 1.55 μm. The obtained near-field distribution of electric fields reveals that resonances in these nano-structures correspond to the even and odd plasmonic modes depending on the geometrical parameters and polarization directions. Considerably large localization factor is obtained for the first odd mode in specific geometrical parameters. Then, this structure is considered to be surrounded by a typical second-order nonlinear dielectric. The effective susceptibility is calculated for the considered structure, using the nonlinear retrieval method, to demonstrate the enhanced second-harmonic generation quantitatively. In order to represent the applicability of the investigated structure in nano-scale light sources and frequency doublers, its second harmonic generation efficiency is compared with the efficiency of the nonlinear dielectric alone with the same dimensions.
Ahmad Salmanogli, Farzin Asghari Sana,
Volume 13, Issue 1 (1-2019)
Abstract
in this work, some of the lattice plasmon quantum features are examined. Initially, the interaction of the far-field photonic mode and the nanoparticle plasmon mode is investigated. We probe the optical properties of the array plasmon that are dramatically affected by the array geometry. It is notable to mention that the original goal of this work is to examine the quantum feature of the array plasmon. For this reason, we consider a system containing array of the plasmonic nanoparticles and quantum dots. For a complete understanding, we analyze the system with the full quantum theory. Notably, the full quantum analyzing enables us to investigate the quantum fluctuation of the array field. Here, for instance, we study the second-order correlation function and report its modeling results.
Mohammadreza Mehdipour, Vahid Ahmadi, Reza Poursalehi,
Volume 14, Issue 1 (1-2020)
Abstract
Topological Insulators are systems where the broken time reversal symmetry gives rise to protected edge modes that support backscatter-free and one-way propagation of electromagnetic waves by opening non-trivial bandgaps. In this study we investigate a one-way topologically protected waveguide in the frequency range of f=6.0 to 8.0 GHz. The time reversal symmetry is broken by an applied magnetic field in the z direction. We show that the waveguide propagates the light in only one direction that can be controlled by the applied magnetic field and no backscattering is present in the waveguide which results in a near 100% transmission of light to the output. Furthermore, we investigate effect of the applied magnetic field on the topological properties of the system by considering the material dispersion of the rods. Our results show that 3 different frequency ranges will be supported by the edge modes at each given magnetic field. By increasing the magnitude of the applied magnetic field, a blue shift in the non-trivial bandgap is seen, where it can be used to tailor the modes for the waveguide.
Zahra Saghi,
Volume 15, Issue 2 (7-2021)
Abstract
Square-core optical fiber is one of the modern optical fibers used in many fields such as astronomical spectroscopy, laser cutting and thermal applications of lasers and beam shaping optics. In this paper, an optical fiber that has a square core with a side of 55 µm is designed for propagating laser light at a wavelength of 1060 nm. Then, using numerical analysis by finite element method (FEM), the distribution of electric and magnetic fields with different polarizations and magnetizations is analyzed for the first three propagating modes of the optical fiber. In the following, the changes of total energy density and power flow are investigated. Finally, the results of the figures and plots are discussed completely.
