3D Finite-Difference Time-Domain (FDTD) Code with Uniaxial Perfectly Matched Layer (UPML) Absorbing Boundaries

This 3D FDTD code implements the Uniaxial Perfectly Matched Layer (UPML) absorbing boundary condition to accurately simulate electromagnetic wave propagation. The simulation employs the Finite-Difference Time-Domain (FDTD) computational method, which discretizes Maxwell's equations in both time and space domains to calculate electromagnetic wave behavior in three-dimensional space. The UPML absorption boundary technique is implemented through specialized anisotropic material layers at the domain edges, effectively eliminating numerical reflections from computational boundaries and significantly enhancing simulation accuracy. The code structure includes key components such as field update equations using central difference approximations, material parameter assignments, and the recursive convolution method for UPML implementation. By utilizing this code, researchers can effectively study electromagnetic wave propagation characteristics in 3D environments and develop applications in computational electromagnetics, antenna design, and photonic device simulation. The implementation features modular design with separate functions for field updates, boundary handling, and results visualization, making it suitable for both educational and research purposes.