More precisely, if the time-dependence of an electromagnetic wave can be assumed to be of the form and the dispersion relation given by for some refractive index distribution, then the electric field solves The Helmholtz equation is used in the modelling of the propagation of electromagnetic waves. UPDATE: Android app now available, see this post for details. Well, spurred on by a shocking amount of spare time, I’ve given it a go here. I casually mentioned that I really should be doing things more rigorously by solving the Helmholtz equation, but then didn’t. A few posts back I was concerned with optimising the WiFi reception in my flat, and I chose a simple method for calculating the distribution of electromagnetic intensity.
