Full-wave finite-difference time-domain analysis of the invisibility cloak mapped to a line segment with isotropic complementary media

Abstract

A dispersive full-wave finite-difference time-domain model is used to study the performance of point mapped and line-segment mapped complementary invisibility cloaking devices. We have used the permittivity and the permeability tensors for conventional elliptic and bipolar cylindrical invisibility cloaks obtained from an effective medium approach in general relativity. In the case of a line-segment mapped cloak we also employ the mapping of the σ-axis in bipolar cylindrical coordinates. In these cloaks, we employ the complementary media both horizontally and vertically. Cloaks with horizontally or vertically arranged complementary media mapped to a point show good performance of cloaking in any case. On the other hand, cloaks with horizontally arranged complementary media mapped to a line-segment, do not show cloaking performance. However, for cloaks with vertically arranged complementary media mapped to a line-segment, cloaking works very well in any cases. These results show improved cloaking performance over the conventional cloaks with perfect electrical conductor mapped to a line-segment. On the other hand, realistic cloaking materials with loss still show cloaking but attenuated backscattering waves exist.