arXiv subjects

Srikumar Sandeep

Publications and source records attributed to Srikumar Sandeep.

4 recordsLinked to original sources

arXiv2018

Fast analysis of spherical metasurfaces using vector wave function expansion

Modeling of spherical metasurfaces using Generalized Sheet Transition Conditions (GSTCs) and Vector Wave Function (VWF) expansion is presented. The fields internal and external to the metasurface is expanded in terms of spherical VWFs and unknown coefficients. GSTCs are used to obtain linear relationships between the unknown coefficients. An overdetermined system of equations are then solved by point matching. The method is quasi-analytical and hence there is no need for meshing which is encountered in conventional computational electromagnetic methods. This results in the method being extremely fast and hence useful for metasurface optimization. The method is validated by two examples. The formulations presented here can be easily extended to multilayered spherical metasurfaces.

physics.class-ph↗

arXiv2018

Simulation of Circular Cylindrical Metasurfaces using GSTC-MoM

A modeling of circular cylindrical metasurfaces using Method of Moments (MoM) based on Generalized Sheet Transition Conditions (GSTCs) is presented. GSTCs are used to link the integral equations for fields on the inner and outer contour of the cylindrical metasurface. The GSTC-MoM is validated by a case of an anisotropic, gyrotropic metasurface capable of two field transformations. The formulations presented here can be used as a platform for deriving GSTC-MoM for 3D spherical and conformal metasurfaces.

physics.comp-ph↗

arXiv2017

Finite Element Modeling of Metasurfaces with Generalized Sheet Transition Conditions

A modeling of metasurfaces in the finite element method (FEM) based on generalized sheet transition conditions (GSTCs) is presented. The discontinuities in electromagnetic fields across a metasurface as represented by the GSTC are modeled by assigning nodes to both sides of the metasurface. The FEM-GSTC formulation in both 1D and 2D domains is derived and implemented. The method is extended to handle more general bianistroptic metasurfaces. The formulations are validated by several illustrative examples.

physics.class-ph↗

arXiv2017

Modeling Study of Laser Beam Scattering by Defects on Semiconductor Wafers

Accurate modeling of light scattering from nanometer scale defects on Silicon wafers is critical for enabling increasingly shrinking semiconductor technology nodes of the future. Yet, such modeling of defect scattering remains unsolved since existing modeling techniques fail to account for complex defect and wafer geometries. Here, we present results of laser beam scattering from spherical and ellipsoidal particles located on the surface of a silicon wafer. A commercially available electromagnetic field solver (HFSS) was deployed on a multiprocessor cluster to obtain results with previously unknown accuracy down to light scattering intensity of -170 dB. We compute three dimensional scattering patterns of silicon nanospheres located on a semiconductor wafer for both perpendicular and parallel polarization and show the effect of sphere size on scattering. We further computer scattering patterns of nanometer scale ellipsoidal particles having different orientation angles and unveil the effects of ellipsoidal orientation on scattering.

physics.optics↗