Monolithically mode division multiplexing photonic integrated circuit for large-capacity optical interconnection.

Area of Science:

• Photonics
• Integrated Optics
• Optical Communications

Background:

• High-capacity optical interconnections are crucial for advanced computing and data centers.
• Photonic integrated circuits (PICs) offer a scalable solution for optical signal processing.
• Mode division multiplexing (MDM) enhances data transmission capacity by utilizing different light modes.

Purpose of the Study:

• To propose and fabricate an on-chip mode division multiplexed (MDM) photonic interconnection system.
• To demonstrate the feasibility of generating, multiplexing, transmitting, demultiplexing, and detecting MDM signals on a single chip.
• To validate the performance of the integrated MDM link for future large-capacity optical interconnections.

Main Methods:

• Fabrication of a monolithically photonic integrated circuit (PIC) comprising a grating coupler, micro-ring modulators, mode multiplexer/demultiplexer, and germanium photodetectors.
• On-chip demonstration of signal generation, multiplexing, transmission, demultiplexing, and detection.
• Testing of 20 Gb/s MDM signals and analysis of power penalties.

Main Results:

• Successful on-chip demonstration of all signal processing stages (generation to detection) within the MDM photonic interconnection system.
• Achieved clear and open eye diagrams for 20 Gb/s MDM signals, confirming signal integrity.
• Measured power penalties indicate good performance of the developed MDM link.

Conclusions:

• The proposed on-chip MDM system is feasible and validated for processing high-speed optical signals.
• The integrated photonic circuit demonstrates potential for enabling large-capacity optical interconnections.
• This technology can be a key enabler for future high-performance computers and big data centers.