Sub-μs switching time in silicon-on-insulator Mach-Zehnder thermooptic switch

We have demonstrated both rise and fall times below 1 μs with 10%-90% modulation in a silicon-on-insulator thermooptical Mach-Zehnder switch. The switch is based on 9-μm-thick and 10-μm-wide single-mode rib waveguides. Very fast switching was achieved by using a differential control method. The switch was driven with a digital signal processor accompanied by simple electronic circuitry.