Monolithically integrated ultrafast all-optical demultiplexer switch

Ultrafast all-optical demultiplexing will be needed to handle optical time domain multiplexed signals in excess of 40 Gb/s. We report a symmetric Mach-Zehnder all-optical switching device that is fabricated using GaAs/AlGaAs multiple quantum well structures and selective area quantum well disordering for the integration. Although the switching is based on carrier-induced nonlinearities, by employing two consecutive control pulses, one to switch the device on and the other to switch the device off, the switching speed is not restricted by the slow carrier relaxation time.