Femtosecond Operation of Symmetric Mach-Zehnder All-Optical Switch and Its Photonic Integration

We demonstrate 200 fs switching and 1.5Tbps demultiplexing with a polarization-discriminating symmetric Mach-Zehnder (PD-SMZ) all-optical switch. Such ultrafast switching was possible, because the switching speed of PD-SMZ is not restricted by slow relaxation time of the highly efficient bandfilling nonlinearity in semiconductors. These results indicate all-optical demultiplexing well exceeding 1 Tbps would be possible. We also report on photonic integration of SMZ, using the Planer Lightwave Circuit technology. With a photonically integrated SMZ, we achieved an extinction ratio better than 12 dB. Its switching speed was limited only by the measurement system in the present experiment, but we anticipate true picosecond switching would be possible.