  Phase-change materials (PCMs) have emerged as promising active elements in
silicon (Si) photonic systems. In this work, we design, fabricate, and
characterize a hybrid Si-PCM optical modulator. By integrating vanadium dioxide
(a PCM) within a Si photonic waveguide, in a non-resonant geometry, we
demonstrate ~ 10 dB broadband modulation with a PCM length of 500 nm.
