An optical switching device (20) includes a substrate (39) and first and second optical waveguides (23, 25) having respective first and second tapered ends (62, 64), which are fixed on the substrate in mutual proximity one to another. A pair of electrodes (36, 38) is disposed on the substrate with a gap therebetween. A cantilever beam (32) is disposed on the substrate within the gap and configured to deflect transversely between first and second positions within the gap in response to a potential applied between the electrodes. A third optical waveguide (21) is mounted on the cantilever beam and has a third tapered end (60) disposed between the first and second tapered ends of the first and second waveguides, so that the third tapered end is in proximity with the first tapered end when the cantilever beam is in the first position and is in proximity with the second tapered end when the cantilever beam is in the second position.