Efficiency-Improved LOD-FDTD Method for Solving Periodic Structures at Oblique Incidence

This letter presents an efficiency-improved locally one-dimensional finite-difference time-domain (LOD-FDTD) method for solving the problems of oblique incident wave on two-dimensional periodic structures. By expressing the extra time derivatives caused by the field transformation technique as the form of the coefficient matrix, and adopting the LOD scheme, the transformed Maxwell's equations were split into two sub-steps. Then, by introducing an auxiliary field variable denoted by e
_z
, two sub-step procedures were reformulated in a much simpler and more concise scheme. The proposed method is unconditionally stable, and more efficient validated by numerical example.