Coupling between arbitrarily rotated dielectric waveguides

Abstract

The coupling between two identical square dielectric waveguides with parallel axes has been studied for various configurations, in which one of the guides was arbitrarily rotated with respect to the other. In one case, the first guide was kept fixed while the second guide was rotated from 0deg; to 180deg;. It was found that the coupling coejcient was maximal when the inclination angle was 0deg; or 180deg; and vanished when it was 90deg;. In another case, one corner of the first guide faced one corner of the second guide. It was found that the coupling coejcient was less than half the maximal value obtained for the previous configuration. This study has a practical aspect; it proposes a possible way to select an appropriate coupling in order to satisfy a given engineering design.