A 100 Gb s^-1 quantum-confined Stark effect modulator monolithically integrated with silicon nitride on Si

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Electrical Engineering

Background:

• Data centers require faster, more energy-efficient transceivers for AI.
• Quantum-Confined Stark Effect (QCSE) modulators offer high-speed, low-power optical modulation.
• Integration of photonic and electronic components is crucial for advanced data center interconnects.

Purpose of the Study:

• To demonstrate a monolithically integrated O-band Ge/SiGe QCSE modulator for high-speed data transmission.
• To achieve ultra-low energy consumption and high performance in optical modulators.
• To enable scalable and cost-effective co-integration of electronic and photonic components.

Main Methods:

• Fabrication of a monolithically integrated O-band Ge/SiGe QCSE modulator on silicon and silicon-on-insulator substrates.
• Integration with silicon nitride (SiN) waveguides using CMOS-compatible processes.
• Wafer-scale growth of multiple quantum-well stacks for large-scale production.

Main Results:

• Achieved 100 Gb/s modulation speed with <1 dB coupling loss.
• Demonstrated ultra-low energy consumption of <63 fJ/bit.
• Maintained >5 dB static extinction ratio across a 20-80 °C temperature range.
• Showcased substrate-agnostic integration with SiN layers.

Conclusions:

• The developed Ge/SiGe QCSE modulator advances high-speed, energy-efficient optical modulation for data centers.
• The scalable integration approach paves the way for next-generation photonic integrated circuits.
• This technology enables cost-effective co-integration of electronic and photonic components for future data center interconnects.