High-efficiency Si optical modulator using Cu travelling-wave electrode

Area of Science:

• Photonics
• Electrical Engineering
• Materials Science

Background:

• Silicon photonics and CMOS integration are key for advanced optical communication.
• Developing efficient and compatible optical modulators is essential for high-speed data transmission.

Purpose of the Study:

• To demonstrate a high-efficiency, CMOS-compatible silicon Mach-Zehnder Interferometer (MZI) optical modulator.
• To explore the use of copper traveling-wave electrodes and doping compensation for improved performance.

Main Methods:

• Fabrication of a silicon Mach-Zehnder Interferometer (MZI) using CMOS-compatible processes.
• Integration of copper traveling-wave electrodes and doping compensation techniques.
• Characterization of electro-optic bandwidth, dynamic extinction ratio, and modulation efficiency.

Main Results:

• Achieved an electro-optic bandwidth exceeding 30 GHz at 1550 nm and Vbias = -5 V.
• Demonstrated a dynamic extinction ratio greater than 7 dB at a 50 Gbps data rate.
• The phase shifter exhibited a modulation efficiency (Vπ·Lπ) of approximately 18.5 V·mm.

Conclusions:

• The developed Cu-photonics technology shows significant potential for future integration of silicon photonics and CMOS circuits on SOI wafers.
• This high-performance optical modulator is a key enabler for next-generation optical interconnects.
• The study highlights the viability of copper interconnects in advanced silicon photonic devices.