Design of Vanadium Dioxide-Based Plasmonic Modulator for Both TE and TM Modes

Based on vanadium dioxide (VO₂) insulator-metal phase transition, a compact plasmonic modulator is designed for both transverse-electric (TE) and transverse-magnetic (TM) polarization modes. The device consists of a Si waveguide and a metal-oxide-semiconductor-type Si-SiO₂-VO₂-Cu hybrid plasmonic waveguide that is inserted into a Si waveguide. By electrically changing the phase of VO₂ from an insulator to a metal, the guidance of the TE and TM modes along the device is greatly suppressed and, hence, we can obtain modulated optical signals. For a 500-nm-long plasmonic modulator operating at a 1.55-μm wavelength, simulation shows an on/off extinction ratio of 3.9 dB for TE and of 8.7 dB for TM mode.