This module simulates the wave propagation through multiple reflecting interfaces in 2D Optical Waveguides using a Bi-Directional Beam Propagation Method based on finite difference split-step, nonparaxial scheme. The method is non-iterative, highly efficient, simulates non-paraxial propagation very accurately and matches RCWA and available experimental results very well. The method can simulate multiple reflecting interfaces in forward and backward directions without any special modifications and with much less computational effort than other Bi-BPM and FDTD methods. Simulation examples have been presented for Facet with High Reflection Multilayer Coatings and Tilted Bragg Gratings (TBGs) in 2D Optical Waveguides. The customized applications for other multiple reflecting interfaces are available on user’s request.