Rigorous Coupled-Wave Analysis of Multilayer Metal-Insulator Aperture-Particle Composite Periodic Arrays

Rigorous coupled-wave analysis (RCWA) is a highly effective approach for tackling the diffraction problem encountered in periodic micro- and nano-structures. This letter proposes an enhanced RCWA method that combines adaptive spatial resolution (ASR) and the normal vector (NV) method to accurately calculate the transmission characteristics of multilayer metal-insulator aperture-particle composite periodic arrays. Applying ASR initially can reduce the required number of harmonics and computational effort, which in turn helps to refine the boundary conditions more effectively using the NV method. Comparative analysis shows that the ASR-NV RCWA algorithm significantly improves convergence speed and efficiency over classical and ASR RCWA methods. Furthermore, results from the ASR-NV RCWA algorithm align well with those obtained from the finite element method and finite difference time domain approaches. This method holds promise for applications in terahertz band bio-detection and communication systems.