In this paper, we first develop the mathematical modeling equations for wave propagation in several transformation optics devices, including electromagnetic concentrator, rotator and splitter. Then we propose the corresponding finite element time-domain methods for simulating wave propagation in these transformation optics devices. We implement the proposed algorithms and our numerical results demonstrate the effectiveness of our modeling equations. To our best knowledge, this is the first work on time-domain finite element simulation carried out for the electromagnetic concentrator, rotator and splitter.

In this paper we establish the explicit expression for two-dimensional (2D) electromagnetic cloaks of arbitrary star shapes without explicit contour expressions of the objects. Furthermore, 2D arbitrary star-shaped time domain cloak models are developed. A new finite element time domain (FETD) scheme is developed to solve the governing equations, and its stability is also proved. Numerical results are presented to confirm our theoretical analysis of the cloak models and the effectiveness of our FETD method. To our best knowledge, this is the first time domain finite element simulation of arbitrary star-shaped cloaks.