This report gives the results of an investigation to analytically determine the effect of a plane dielectric interface upon the radiation loss of a curved channel dielectric waveguide embedded in a dense substrate and bent in a plane parallel to that of the material interface. The radiation loss from bent dielectric waveguides is of interest for a variety of potential applications in integrated optics. Knowledge of the factors influencing the radiation from bend dielectric waveguides will allow the design of integrated optical component characteristics which, in one application, may result in decreased radiation to conserve signal energy or which, in another application, may achieve enhanced radiation effects in order to optimize the coupling between various optical waveguides. An obvious example for which the conservation of signal energy is of prime concern is the dielectric fiber transmission line used in simple point-to-point data transfer applications. (Author).

The radiated power and the radiation pattern have been studied theoretically for a dielectric slab waveguide. The configuration consists of two semi-infinite slabs joined by a circular bend. The results indicate that the discontinuities at the transitions between the straight slabs and the bend cause the radiation to differ significantly from the radiation of a bend of the same size but being part of a uniform circular structure rather than being joined to two straight slabs. The radiated power is found to vary inversely as the square of the radius of curvature, and the radiation pattern is composed of many closely spaced narrow lobes. As the radius of curvature of the bend increases the lobes become more numerous and more closely spaced.