Polarization conversion by reflection in a thin-film grating.
A dielectric-film waveguide with a grating etched on its film-cover interface can be used as a polarization converter. The e wave can be converted into the h wave and vice versa if the guided wave is incident obliquely to the grating vector. The polarization converter is analyzed by use of a quasi-optic technique. A high degree of polarization-conversion efficiency is achieved by a suitable choice of the grating length. The Bragg angles of incidence and observation, the maximum polarization-conversion efficiency, and the frequency and the angular selectivity are all found to increase with an increase in the grating period. An illustrative numerical example is presented.
Seshadri
S R
SR
s.r.seshadri@worldnet.att.net