A new analysis of electromagnetic scattering from two-dimensional electromagnetic band-gap structures

Electromagnetic band-gap (EBG) structures (also known as photonic crystals in the optical area) have received much attention for their potential application to optical waveguides, antennas, lasers and fibers. We describe a novel formula for analyzing the electromagnetic scattering from inhomogeneous EBG structures using the lattice sums technique and isolated T-matrices. The method is very efficient and accurate and is suitable for multilayer structures, since the formula is in S-matrix form based on space harmonics. The method avoids the use of the aggregate T-matrix, with which is easy to accumulate computing errors. The modification not only eliminates the complex computation of the aggregate T-matrix, but also widely expands its applicable scope. The effectiveness and computing accuracy are confirmed by numerical examples.