CUHK develops all-optical signal processor to break AI data centre transmission bottleneck

2026-06-22
Media Release

A research team led by Professor Huang Chaoran from Department of Electronic Engineering has developed a novel integrated all-optical signal processor (OSP) to address the massive data transmission demands of next-generation AI systems, particularly for high-speed links between multiple data centres.

Built on a silicon photonic chip, the OSP processes optical signals directly in the light domain, correcting distortions in real time without converting them into electrical signals. This approach significantly improves transmission speed, reduces latency and lowers energy consumption compared with conventional digital signal processing (DSP).

Experimental results demonstrate that the OSP achieves an aggregate data rate of 1.6 Tb/s with latency below 60 picoseconds and energy consumption of only tens of femtojoules per bit. These results address key performance bottlenecks in current communication technologies and offer a promising solution for ultra‑low‑latency, energy‑efficient AI computing. The findings have recently been published in the leading international academic journal Science.

Rapid AI growth drives demand for high-speed transmission across large-scale distributed data centres

As AI systems increasingly rely on distributed computing across multiple data centres, fast and reliable data exchange has become critical. However, conventional electronic signal processing struggles to keep up with rising transmission speeds and associated signal distortions.

“Optical fibre communications form the backbone of modern data transmission and data centre interconnect technologies. However, conventional data centre interconnect technologies are increasingly struggling to keep pace with the scale and speed required by modern AI systems,” said Professor Huang Chaoran, Assistant Professor in the Department of Electronic Engineering, CUHK. “As transmission rates continue to rise, signal distortion becomes more severe, and if signal processing still relies on electronic methods, it can also introduce severe latency and significant power consumption.”

Correcting distorted signals directly with light for greater efficiency

To address these challenges, Professor Huang’s team, together with researchers from Huazhong University of Science and Technology (HUST) and Fudan University (FDU), has developed the programmable OSP, which can flexibly compensate for various signal impairments, including chromatic dispersion and nonlinear distortions. Its design draws inspiration from neuromorphic computing and machine learning, enabling more accurate signal correction.

The OSP also demonstrates strong scalability and adaptability across different transmission conditions, wavelengths and data formats, and has the potential to significantly expand optical fibre capacity.

This research marks an important step forward in optical communication, highlighting a future where light is used not only to transmit but also to process information, advancing next‑generation communication and computing technologies.

 

More details: https://www.cpr.cuhk.edu.hk/en/press/cuhk-develops-all-optical-signal-processor-to-break-ai-data-centre-transmission-bottleneck-delivering-1-6-tb-s-throughput-and-sub-60-picosecond-latency-to-enable-green-ai-supercomputing/

 

More information about the research: Professor Huang Chaoran is the corresponding author. Other contributing authors of this work include Wang Benshan (first author), Xiao Qiarong (co-first author), Xu Tengji, Fan Li and Liu Shaojie from CUHK; and collaborators (Professor Kong Qiuqiang from CUHK, Professor Dong Jianji from HUST, and Professor Zhang Junwen from FDU). The full text can be found at https://www.science.org/doi/10.1126/science.ady5344.

A research team led by CUHK has developed a novel integrated all-optical signal processor (OSP) to address the massive data transmission demands of next-generation AI systems. Team members include Assistant Professor in the Department of Electronic Engineering Professor Huang Chaoran (front row middle), PhD students Wang Benshan (back row, 3rd left) and Xiao Qiarong (front row, 1st left).

Distributed data centres rely on high-speed optical interconnects to support large-scale AI. However, as transmission speeds continue to increase, signal distortion, latency and power consumption pose major challenges. The OSP developed by the CUHK-led team can correct distortions in real time before the optical signal is converted into an electrical signal. With a latency below 60 picoseconds and extremely low energy consumption, it can help increase transmission capacity and accelerate AI training across data centres.

The OSP architecture comprises three photonic reservoirs and eight readout channels. By precisely tuning the optical delay lines on the chip, the research team enables the system to achieve extremely high temporal sampling resolution, allowing it to process high-speed optical signals more effectively.

The packaged OSP chip with electrical wire bonds and an optical fibre array.

Comparison of the OSP’s chromatic dispersion compensation performance.

(Left) Under the test conditions, the OSP corrects signal distortion more effectively than conventional DSP-based methods.

(Right) Compared with previously reported optical processors, the OSP enables high-speed data processing at the 200 Gbit/s per channel level.Compensation performance of the OSP under bandwidth limitations and nonlinear effects.

(A–F) Experimental results show that signal impairments and device bandwidth limitations degrade signal quality. After applying the OSP, the signals become significantly clearer and of higher quality.

(G–H) Under nonlinear effects (such as high-power transmission), the OSP performs better than conventional DSP-based methods.

Validation of OSP programmability, demonstrating its ability to adapt flexibly to different transmission conditions.

(A–D) The OSP maintains good signal quality across different wavelengths, data rates and modulation formats.

(E) The system can operate stably after simple training.

(F) The OSP can be adjusted according to different application requirements, showing strong flexibility.

The OSP supports high-speed data centre interconnect transmission with a total rate of up to 1.6 Tb/s

(A) An illustration of a high-speed optical transceiver integrated with the OSP, which can simultaneously process eight wavelength channels and correct distorted optical signals.

(B) Compared with unprocessed transmission or conventional methods, the OSP significantly reduces transmission errors.

(C) When combined with a small amount of DSP, the OSP can further improve long-distance transmission performance.