2D FDTD Band Solver Introduction
The band solver in OptiFDTD is an integrated CAD tool and simulation engine for analyzing the photonic crystal and photonic band gap structure. Currently it employs the FDTD method and generates band-diagrams.
Simulation Concept
As we know, the periodic structure or the lattice structure has the mode selection function. The task of the band solver is to find these mode positions based on one or several basic lattice cell. The key points for FDTD simulation come from: How can the FDTD method extract the mode? How can the FDTD…
Bloch’s Boundary Condition
Bloch’s theorem tells us that for periodic structure, field components have the following properties: where R is the lattice vector, k is the wave vector. Equation 60 is the boundary condition used in the OptiFDTD band solver. Initial excitation Unlike conventional FDTD simulations where time domain excitation is continuous wave and lasts on only some time steps,…
References
[1] J. B. Pendry, “Calculating photonic band structure”, J. Phys., No. 8, 1085-1108, 1996. [2] A. J. Ward, J.B. Pendry, ” Calculating photonic Green’s functions using a non-orthogonal finite difference time-domain method”, PACS.