General design of fiber-compatible integrated-optical S-bends, power splitters, and directional couplers

Integrated-optical waveguide components are normally designed by either a semianalytical method, such as the effective- index method,1 or a numerical-integration technique, e.g., a beam-propagation method.2 Semianalytical methods are simple and generally give a good understanding of the working principles of the devices. However, they are rarely accurate enough for actual design. Numerical-integration methods are normally accurate but are also very time consuming (calculation times of the order of hours).