The geometrical phase of modulated waves propagating in dispersive media (Q1376787)

The author considers the behaviour of the so called ``momentary frequency'' within pulses, and provides a geometrical approach for the analysis. An example discussed is the \(\text{TE}^{10}\) in the form of a rectangular pulse within a rectangular waveguide. In the general analysis a phase space is into a hemisphere, and a vector is introduced analogous to the Jones vector of polarisation optics.