Runge-Kutta-based iterative Maxwell solver for large-scale nanostructures

An iterative numerical solution to the Maxwell equations, with Runge-Kutta-based beam propagation method (RK-BPM) in the k-domain developed by H. Zhong <i>et al</i>. [Opt. Express28, 11074 (2020)10.1364/OE.388376] as the iteration kernel, is presented in this work to deal with the simulation of micro-/nanostructures, particularly for those in large sizes. This method extends the previous work on the RK-BPM by incorporating with the iterative boundary condition scheme from A. Junker and K. H. Brenner [J. Opt. Soc. Am. A35, 377 (2018)10.1364/JOSAA.35.000377], so to make it capable of modeling complex structures with multiple internal reflections with both high accuracy and efficiency.