Efficient Implementation of Rigorous Coupled-Wave Analysis for Analyzing Binary Gratings

In this letter, the conventional rigorous coupled-wave analysis method is improved by using the Cayley-Hamilton theorem. Using the proposed method, the forward and backward diffraction efficiencies of each order are solved directly from the eigenmatrix. At the same time, the calculation results of the conventional method, the proposed method, and the CST simulations are in good agreement with each other. The results show that the proposed method has obvious advantages in computational efficiency.