PERFORMANCE OF S-BENDS FOR INTEGRATED-OPTIC WAVE-GUIDES

The performance of S-bends, which are used for connecting waveguides o ffset with respect to each other, is very important in integrated-opti c waveguide circuits. Several approaches for the design of S-bends hav e been reported in the literature. These include, in particular, desig ns based on simple sinusoidal curves as well as relatively complicated , bur more general, polynomial curves. This paper reports a comparison of the calculated pure bend loss of such S-bends for a typical silica -based waveguide operating at a wavelength of 1550 nm. It is shown tha t the simple cosine S-bands yield a performance which is close to that obtained from the general polynomial curve-based S-bends. Design curv es are also presented for these two types of S-bends. The calculations are based on the analytical expression for bend loss proposed by Marc use. (C) 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 2 89-292, 1998.