We present an exact solution for the plane wave mode functions of a massless, minimally coupled scalar propagating in an arbitrary homogeneous, isotropic and spatially flat geometry. Our solution encompasses all previous solvable special cases such as de Sitter and power law expansion. Moreover, it can generate the mode functions for gravitons. We discuss some of the many applications that are ...

The refraction phenomenon at the interface of an ordinary material and a lossy metamaterial has been investigated. For oblique incidence on the lossy metamaterial, the planes of constant amplitude of the refracted wave are parallel to the interface and the plane of constant phases make a real angle with the interface (real refraction angle). The real refraction angle and hence, the real refract...

In this paper, a photonic crystal structure for comparing two bits has beenproposed. This structure includes four resonant rings and some nonlinear rods. Thenonlinear rods used inside the resonant rings were made of a doped glass whose linearand nonlinear refractive indices are 1.4 and 10-14 m2/W, respectively. Using Kerr effect,optical waves are guided toward the correc...

Abstract: In this paper, we aim to design and propose a novel structure for all-opticalhalf subtractor based on the photonic crystal. The structure includes two optical switches,one power splitter, and one power combiner. The optical switches are made of theresonant rings which use the nonlinear rods for dropping operation. The footprint of thedesigned structure is about...

If the sampled diffraction pattern due to a planar object is used to reconstruct the object pattern by backpropagation, the obtained pattern is no longer the same as the original. The effect of such sampling on the reconstruction is analyzed. The formulation uses the plane-wave expansion, and therefore the provided solution is exact for wave propagation in media where scalar wave propagation is...

We derive an exact analytic expression for the high-temperature limit of Casimir interaction between two Drude spheres arbitrary radii. Specifically, we determine free energy by using scattering approach in plane-wave basis. Within a round-trip expansion, are led to consider combinatorics certain partitions round trips. The relation and capacitance matrix is discussed. Previously known results ...

In this paper, four channel demultiplexer is designed using two-dimensional photonic crystal for Coarse Wavelength Division Multiplexing applications. The proposed demultiplexer consists of bus wave guide, output wave guide and a cavity. The channel selection is done by having a cavity with unique refractive index. The two dimensional finite difference time domain and plane wave expansion metho...

Original method for studying the dispersion characteristics of photonic crystals – media with a dielectric constant that varies periodically in space is considered. The based on representation wave functions and permittivity periodic medium form Fourier series their subsequent substitution into equation, which leads to formulation equation. Using latter, each value vector it possible determined...

in this work g'/g-expansion method has been employed to solve (2+1)-dimensional dispersive long wave equation. it is shown that g'/g-expansion method, with the help of symbolic computation, provides a very effective and powerful mathematical tool, for solving this equation.

We present a study on structural and electronic properties of bulk platinum and the two surfaces (111) and (100) comparing the Gaussian and plane wave method to standard plane wave schemes, normally employed for density functional theory calculations on metallic systems. The aim of this investigation is the assessment of methods based on the expansion of the Kohn-Sham orbitals into localized ba...