A quasi-optical approximation is constructed for waves in media for which the dispersion relation has repeated solutions, the order of repetition being constant throughout the medium. By a suitable choice of the basis vectors representing the polarizations corresponding to the repeated solution, the equations for the amplitude may sometimes be uncoupled. An important application is to radio waves in an isotropic absorbing medium.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.