Hi, I'm a physicist intern that has some problems with Optics simulations; I'm very interested in doing some Beam Propagation Method (BPM) simulation, but the information online is not that good for begginers in the area. Can anyone advise me on books, journals or such that might help me learn the basics (and maybe more) of this method? Someone with experience doing BPM will be great. Thanks in advance! P.S.: I have moderate knowledge of Python for simulation (especially matplotlib), but not so much of Mathematica, but I can learn if it's needed.