Electrically active optical bifurcation: BOA

Abstract

We report the realization of an electro‐optical switch based on the interference between modes in a two‐mode waveguide (equivalent to a directional coupler with no gap between the guides). Switching is achieved by uniformly changing the refractive index of the guide. This permits attaining the two switching states even in the presence of fabrication errors, with a very simple electrode configuration. Crosstalks of −16 and −18 dB for command voltages of 8 and −18 V have been obtained for such a structure realized in Ti : diffused lithium niobate.