In weakly nonlinear systems, the main effect of cubic nonlinearity on wave propagation is an amplitude-dependent correction dispersion relation. This phenomenon can manifest either as a frequency shift or wavenumber depending whether excitation prescribed initial condition boundary condition, respectively. Several models have been proposed to capture shifts observed when system subjected harmon...

The polybenzene units BTX 48, X=A (armchair) and X=Z (zig-zag) dimerize forming “eclipsed” isomers, the oligomers of which form structures of five-fold symmetry, called multi-tori. Multi-tori can be designed by appropriate map operations. The genus of multi-tori was calculated from the number of tetrapodal units they consist. A description, in terms of Omega polynomial, of the two linearly peri...

The finite-difference time-domain (FDTD) method is used to obtain numerical solutions of infinite periodic structures without resorting to the complex frequency-domain analysis, which is required in traditional frequency-domain techniques. The field transformation method is successfully used to model periodic structures with oblique incident waves/scan angles. Maxwell’s equations are transforme...

2014 Since high-resolution electron micrographs of dodecagonal Ni-Cr quasicrystals are similar in contrast to those of several closely related periodic phases, it has been argued that dodecagonal quasicrystals can be described as a decoration of a dodecagonal quasiperiodic tiling with the same structural units as occur in these periodic phases. In order to corroborate this hypothesis, electron ...

In this paper, we have reported the fabrication of two-dimensional photonic crystals, using a direct writing method in azo polymers. Periodic structures have been fabricated using the interference patterns of two coherent laser beams. The frequency response of the initial one-dimensional structure shows an attenuation of 19.3dB at 1554nm. The twodimensional structure shows 8.3dB and 11.3dB of a...

Based on holographic interferometry technique, we develop an alternative method for micrometer-sized periodic structures design. The optical setup with 2D spatial light modulator for periodic structures generation is presented. It is shown that this innovative method made possible the rapid generation of periodic structures employing diffractive masks and phase modulation based on multiple beam...

This paper proposes a spectral-domain approach to the electromagnetic scattering problem of lamellar grating with defects. The fields in imperfectly periodic structures have continuous spectra in the wavenumber space, and the main problem of the spectral-domain approach is connected to the discretization scheme on the wavenumber. The present approach introduces the pseudo-periodic Fourier trans...

By developing the terahertz (THz) technology, in addition to generators and detectors of THz waves, the existence of some tools such as modulators and filters are needed. THz filters are important tools for various applications in the field of chemical and biological sensors. Linear and nonlinear optical properties of the graphene have attracted lots of attention. In fact graphene exhibits vari...