25Gb/s 1V-driving CMOS ring modulator with integrated thermal tuning

Area of Science:

• Photonics and optoelectronics
• Silicon photonics
• Integrated optics

Background:

• Future exascale supercomputers require high-speed, low-power optical interconnects.
• Existing modulators face challenges in meeting these demanding performance metrics.

Purpose of the Study:

• To report a novel high-speed ring modulator suitable for optical interconnects in exascale supercomputers.
• To characterize its modulation speed, energy efficiency, and thermal tuning capabilities.

Main Methods:

• Fabrication of a ring modulator using a 130 nm Silicon-on-Insulator (SOI) CMOS process.
• Utilizing a PN junction in carrier-depletion mode for high-speed modulation.
• Employing microwave characterization and circuit modeling for performance analysis.

Main Results:

• Achieved 25 Gb/s modulation speed with an extinction ratio >5 dB using only 1V driving voltage.
• Demonstrated a thermal tuning efficiency of 0.19 nm/mW for broad wavelength operation.
• Estimated modulation energy of approximately 7 fJ/bit with a compact 400 μm² footprint.

Conclusions:

• The developed ring modulator exhibits ideal qualities for future exascale supercomputer optical interconnects.
• Its high speed, low power consumption, and compact size make it a promising solution.
• The device's performance highlights advancements in silicon photonics for high-performance computing.