Peking University develops unified silicon photonic coherent link for all distances
Researchers presented a coherent silicon photonic architecture operating without optical amplification over short links and reaching over 4,400 km.

Researchers from Peking University, SiFotonics Technologies, and the Chinese Academy of Sciences have demonstrated a unified silicon photonic coherent platform designed for all-distance optical communications, according to a study published in Nature Communications doi.org
Nature Communicationsdoi.orgOpen source ↗. The architecture addresses the traditional division between short-reach links, which typically rely on intensity modulation due to hardware and energy constraints, and long-haul systems that require coherent transmission for high capacity.
Laser specifications and integrated transceiver
The platform utilizes a laser integrated with an ultralow-loss silicon nitride external cavity doi.org
Nature Communicationsdoi.orgOpen source ↗. This configuration achieves a direct optical output power of 70 mW, a sub-kilohertz spectral linewidth, and a wall-plug efficiency of 13.7%
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Nature Communicationsdoi.orgOpen source ↗. Paired with silicon photonic transceivers, the system provides high spectral efficiency while mitigating the hardware complexity that previously restricted coherent optical architectures to long-distance infrastructures
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Nature Communicationsdoi.orgOpen source ↗.
Short-reach throughput and long-haul transmission
During experimental evaluations, the platform supported unamplified short-distance data transmission across 256 wavelength channels, reaching an aggregate data rate of 81.92 Tb/s doi.org
Nature Communicationsdoi.orgOpen source ↗. For long-distance communications, the coherent platform maintained transmission over distances exceeding 4,400 km
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Nature Communicationsdoi.orgOpen source ↗. Furthermore, the system demonstrated wavelength switching and the re-establishment of data transmission on timescales of tens of microseconds, enabling dynamic wavelength-routed optical connectivity
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Nature Communicationsdoi.orgOpen source ↗.



