Showing papers by "Qaisar Abbas Naqvi published in 2013"

Scattering of electromagnetic plane wave from a chiral cylinder placed in chiral metamaterials

Abstract: Analytical solution of vector wave equation describing the scattering of electromagnetic plane waves from an infinitely long circular chiral cylinder placed in another chiral metamaterial is presented. Cylindrical vector wave functions are used to express the fields both inside and outside the circular cylinder. The unknown are determined by applying the appropriate boundary conditions at the cylindrical interface. The numeric results are presented taking different combinations of metamaterials for inner and outer mediums of the cylinder. For this purpose chiral and/or chiral nihility cylinder placed in chiral and/or chiral nihility mediums are considered. Extreme cases of permittivity and permeability corresponding to PEC and PMC cylinder are also considered.

Effects on reflected and transmitted powers of planar stratified structures involving chiral nihility metamaterials

Abstract: Behavior of different planar multilayer periodic structures due to plane wave excitation has been studied using the transfer matrix method. Multilayer structure is composed of odd number of slabs and the layers at odd locations have same characteristics and layers at even locations have same characteristics. For each structure, layers at odd locations are of chiral nihility metamaterial whereas three different cases are considered for layers at even locations, i.e., dielectric, chiral and chiral nihility. Effects of polarization rotation due to the optical activity of material's chirality is studied with respect angle of incidence and frequency in THz region. Chiral nihility adds property of transparency to the structure for normal incidence. Chiral nihility-chiral nihility structure for normal incidence yields transparency whereas same structure for oblique incidence yields total rejection at higher frequencies.

of planar stratified structures involving chiral

Abstract: 2 6 Abstract. Behavior of different planar multilayer periodic structures due to plane wave excitation has been studied using 7 the transfer matrix method. Multilayer structure is composed of odd number of slabs and the layers at odd locations have 8 same characteristics and layers at even locations have same characteristics. For each structure, layers at odd locations are of 9 chiral nihility metamaterial whereas three different cases are considered for layers at even locations, i.e., dielectric, chiral and 10 chiral nihility. Effects of polarization rotation due to the optical activity of material's chirality is studied with respect angle 11 of incidence and frequency in THz region. Chiral nihility adds property of transparency to the structure for normal incidence. 12 Chiral nihility-chiral nihility structure for normal incidence yields transparency whereas same structure for oblique incidence 13 yields total rejection at higher frequencies. 14

Focusing, power tunneling and rejection from chiral and/or chiral nihility/nihility metamaterials layers

Abstract: Focusing of electromagnetic plane wave from a large paraboloidal re∞ector, composed of layers of chiral and/or chiral nihility metamaterials, has been studied using Maslov's method. As a flrst step, the transmission and re∞ection of electromagnetic plane wave from two parallel layers of chiral and/or chiral nihility metamaterials are investigated using transfer matrix method. The efiects of change of angle of incidence, chirality parameters and impedances of layers are noted and discussed. Special cases by taking extreme values of permittivity of second layer, while assuming value of corresponding chirality equal to zero, are also obtained for validating the methodology. These special cases are equivalent to re∞ection from a perfect electric conductor backed chiral layer and nihility backed chiral layer, respectively. Results of re∞ection from parallel layers have been utilized to study focusing from a large paraboloidal re∞ector. The present study, on focusing from a paraboloidal re∞ector, not only unifles already published work by various researchers but also provides better understanding of the problem.

Effects of Planar Periodic Stratified Chiral Nihility Structures on Reflected and Transmitted Powers

Abstract: Behavior of planar multilayer periodic structures due to plane wave excitation has been studied using the transfer matrix method. Multilayer structure is taken with periodicity two. That is, layers at even and odd locations repeat themselves. Layers at odd locations are of chiral nihility metamaterial whereas three different cases for layers at even locations are considered, i.e., dielectric, chiral and chiral nihility. Effects of polarization rotation due to the optical activity is studied with respect to the angle of incidence and frequency in terahertz domain. Chiral nihility introduces property of transparency to the structure for normal incidence while complete rejection is observed for chiral nihility-chiral nihility structure at oblique incidence.

Scattering from a buried perfect electromagnetic conductor of circular cylindrical shape and coated by a chiral material

Abstract: The scattering effects of different types of chiral materials used as coating on a perfect electromagnetic conductor (PEMC) circular cylinder buried in a dielectric half space have been investigated in this paper. The coating layers of double positive (DPS) chiral, double negative (DNG) chiral, and chiral nihility have been considered in the analysis. The spectral plane wave solution is used to handle the multiple interactions between the buried cylinder and the dielectric interface separating the two half spaces. Numerical results obtained for scattering of a perpendicularly polarized electromagnetic plane wave from this configuration have been presented.

Focusing, Power Tunneling and Rejection from Chiral and/or Chiral Nihility/Nihility Metamaterials Layers

Abstract: Focusing of electromagnetic plane wave from a large size paraboloidal reflector, composed of layers of chiral and/or chiral nihility metamaterials, has been studied us- ing Maslov's method. First, the transmission and reflection of electromagnetic plane wave from two parallel layers of chiral and/or chiral nihility metamaterials are cal- culated using transfer matrix method. The effects of change of angle of incidence, chirality parameters and impedances of layers are noted and discussed. Special cases by taking very large and small values of permittivity of second layer, while assuming value of corresponding chirality equal to zero, are also treated. These special cases are equivalent to reflection from a perfect electric conductor backed chiral layer and nihility backed chiral layer, respectively. Results of reflection from parallel layers have been utilized to study focusing from a large size paraboloidal reflector. The present study, on focusing from a paraboloidal re°ector, not only unifies several published works conducted by different researchers but also provides better understanding of new cases.