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.