Integrated multi-port multi-wavelength coherent optical source for beyond Tb/s optical links

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Data Communication

Background:

• Optical frequency combs (microcombs) are crucial for large-scale optical links in data centers and AI.
• Existing demultiplexers often have high power consumption, limiting scalability.
• Autonomous tracking of comb lines is essential for stable optical communication.

Purpose of the Study:

• To demonstrate a multi-wavelength multi-port source using a Kerr microcomb and an integrated demultiplexer.
• To achieve autonomous locking and tracking of microcomb lines.
• To significantly reduce the power and energy consumption of wavelength demultiplexing.

Main Methods:

• Utilized a soliton microcomb with 200 GHz mode-spacing and 53% efficiency.
• Implemented Mach-Zehnder interferometer- and ring resonator-based wavelength demultiplexers.
• Employed capacitive optical phase shifters with zero static power consumption and a single control unit.

Main Results:

• Achieved a total demultiplexer power consumption of 2.4 mW.
• Demonstrated record low demultiplexer energy consumption: 10 fJ/b (8-channel) and 2.5 fJ/b (32-channel) at 32 Gb/s/channel.
• Successfully achieved autonomous locking and tracking of comb lines.

Conclusions:

• The developed microcomb-based source offers a significant improvement in demultiplexer energy efficiency.
• This technology is highly promising for energy-efficient optical links in data centers and AI systems.
• The autonomous tracking capability enhances the robustness of optical communication systems.