Further Properties of Lamellar Grating Resonance Anomalies

Abstract

The study of the infinitely conducting lamellar grating resonance anomalies is extended to arbitrary wavelengths and angles of incidence, and the behaviour of the trajectories is found theoretically and numerically. The discussion of resonances for varying wavelength is unified with that for varying angle of incidence. The phenomena of ‘repulsion of anomalies’ and ‘exchange of identity’ are explained. Infinite conductivity results are compared with those for various finite conductivities, and it is shown that there is a close similarity between them, suggesting that the ideas developed for the former case have a wider validity. This is seen to be so when a brief survey is made of results for other grating profiles and arbitrary values of conductivity.