INFLUENCE OF PARASITIC COUPLINGS IN BENDING SECTIONS ON DIRECTIONAL COUPLER OPTICAL SWITCHING

The modified switching conditions of directional coupler optical switc hes, in the presence of parasitic couplings in bending sections, are d iscussed by means of the coupled mode theory. As expected, a parallel section's length needs to be adjusted by less than the coupling length l(c) (=pi/2 kappa(0)), depending on the amount of parasitic coupling. For weak parasitic coupling, however, the switching voltage does not need to be altered but maintains the same value as without parasitic c oupling.