Mid-infrared hybrid Si/VO₂ modulator electrically driven by graphene electrodes

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Mid-infrared (mid-IR) applications require efficient integrated optics platforms.
• Developing high-speed modulators for mid-IR wavelengths remains a significant challenge.

Purpose of the Study:

• To present an ultra-compact, high-speed hybrid silicon/vanadium dioxide (Si/VO2) modulator operating at 3.8 μm.
• To leverage graphene's electrical and thermal properties to enhance modulator performance.

Main Methods:

• Utilized electrical actuation to induce reversible insulating-metal phase transitions in VO2.
• Employed graphene's thermal properties to accelerate VO2 phase transition heating and dissipation.
• Conducted optical and thermal simulations to evaluate modulator performance.

Main Results:

• Achieved an extinction ratio of 4.4 dB/μm and insertion loss of 0.1 dB/μm.
• Demonstrated a high modulation speed of 23 ns.
• Showcased potential for a 10 dB/μm modulation depth at reduced speeds.

Conclusions:

• The hybrid Si/VO2 modulator offers a promising solution for high-speed mid-IR integrated optics.
• Graphene integration significantly improves modulation speed and performance.
• The device design provides a tunable trade-off between modulation depth and speed.