Effective Electro-Optical Modulation with High Extinction Ratio by a Graphene-Silicon Microring Resonator

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Graphene's unique properties (high carrier mobility, broad absorption) enable novel optoelectronic applications.
• Tuning graphene's Fermi level allows for electro-optical modulation and optical switching.
• Limited graphene-light interaction in conventional devices hinders high modulation depth.

Purpose of the Study:

• To comprehensively study the graphene-microring resonator interaction.
• To investigate its influence on optical modulation depth in graphene-silicon devices.
• To demonstrate high-performance electro-optical modulation and switching.

Main Methods:

• Fabrication of graphene-silicon microring resonator devices.
• Characterization of optical modulation depth and electro-optical switching.
• Application of varying bias voltages and waveforms.

Main Results:

• Demonstrated a high modulation depth of 12.5 dB in graphene-silicon microring devices.
• Achieved on-off electro-optical switching with a 3.8 dB extinction ratio.
• Utilized a low bias voltage of 8.8 V and a 4 V peak-to-peak square waveform.

Conclusions:

• Graphene-microring resonator interaction significantly enhances optical modulation depth.
• High-performance electro-optical modulation and switching are achievable with graphene-silicon devices.
• These findings pave the way for advanced optoelectronic modulators and switches.