Length minimization in integrated optical circuits incorporatingdirectional couplers and curved sections

An analysis is presented that describes minimization of overall channel waveguide length in integrated optical circuits incorporating directional couplers and curved sections. Calculations are presented for LiNbO₃, GaAlAs, and SiO₂-Si based optical channel waveguides. The results demonstrate the presence of a minimum total length corresponding to a particular degree of field confinement. The value of overall length at the minimum is shown to be significantly lower than that for other values of field confinement allowing single-mode operation