All-optical modulators are likely to play an important role in future chip-scale information processing systems. In this
work, through simulations, we investigate the potential of a recently reported vanadium dioxide (VO2) embedded silicon
waveguide structure for ultrafast all-optical signal modulation. With a VO2 length of only 200 nm, finite-differencetime-
domain simulations suggest broadband (200 nm) operation with a modulation greater than 12 dB and an insertion
loss of less than 3 dB. Predicted performance metrics, including modulation speed, modulation depth, optical bandwidth,
insertion loss, device footprint, and energy consumption of the proposed Si-VO2 all-optical modulator are benchmarked
against those of current state-of-the-art all-optical modulators with in-plane optical excitation.