Basic physics of laser propagation in hollow waveguides

The basic theory of laser propagation in hollow waveguides is considered in the context of laser-plasma physics. The physical model of waves reflectin g between the guide walls is used to show that there is a discrete series o f modes, and to give the mode dispersion relation and losses in terms of a given reflectivity. The mathematical connection between this model and the solution of Maxwell's equations for lossless propagation in a cylinder is g iven. Thus the solutions for low loss propagation for any given reflectivit y can be obtained, provided it is close to 1. Results are given using Fresn el reflectivity for perfect dielectric and finite conductivity waveguides. The relationship of the breakdown intensity in dielectric waveguides to kno wn breakdown intensities is also derived. The practical implications for th e guiding of intense laser pulses and the limitations of the model are disc ussed. The theory is shown to explain, at least qualitatively, a number of previous experimental results.