 Beam propagation method

The Beam Propagation Method (BPM) is a numerical technique used to simulate the propagation of electromagnetic waves, particularly in the context of optics and photonics. It is especially useful for analyzing waveguides and optical devices where light experiences significant changes in direction, such as in fiber optics, integrated optical circuits, and other photonic structures. ### Key Aspects of BPM: 1. **Wave Equation**: BPM is based on the solution of the scalar wave equation or the Helmholtz equation.