Ultrafast optical switching of femtosecond 1550 nm pulses in silicon modulators (Conference Presentation)

A key challenge to widespread implementation of silicon photonics is achieving optical switching at ultrafast speed and ultralow power using on-chip silicon modulators.  Here we report experiments demonstrating that the ultrafast photo-induced phase transition in VO2 can be harnessed for all-optical in the telecommunications band when small VO2 volumes are integrated within a silicon waveguide.  "On"-to-"off" switching speeds in this in-line modulator are less than 1 ps, thus consistent with Tbps speeds, and switching energies near threshold are less than 500 fJ for modulation depths near 6 dB.  Early results showing significant reductions in switching energies in hybrid VO2:Si ring resonators will also be presented.