M.M. Ameen, S. M. A.; H. Mansour, M. A Simple and General Analytical Expression for Calculating Crosstalk in Multiwaveguide Directional Couplers Using Finite Differences Method. JK-Physics 2020, 11 (02), 6-14. https://doi.org/10.31257/2018/JKP/2019/110202.