THEORETICAL S-BEND PROFILE FOR OPTIMIZATION OF OPTICAL WAVE-GUIDE RADIATION LOSSES

High-density optical integrated circuits require curved waveguides wit h low radiation losses. This letter deals with the optimization of S-b end profiles that produce a minimum of pure bending losses. The analyt ical profile that optimizes these losses in ''low-slope'' S-bends is p resented, assuming an exponential representation of bending losses per unit length. On the other hand, a numerical optimization procedure ha s been developed for curved waveguides with arbitrarily representation of the unitary bending losses. Some results are provided for LiNbO3 w aveguides, including a comparison between the optimal profile and othe r usual S-bend profiles.