By Da Cheung
China Information Communication Technologies Group (CICT) has just announced it’s achieved a massive leap in data capacity — a record-breaking optical transmission speed of 2.5 petabits per second (Pb/s) over a 24-core single-mode fiber spanning 10.3 kilometers.
The breakthrough, disclosed on March 24, means that at the speed of 2.5 Pb/s, users could theoretically download 14,000 high-definition 4K movies — each 20 gigabytes in size — in a single second.
With large language models and vast data centers driving an explosive growth in network traffic, particularly the massive data flows required to interconnect AI data centers, traditional single-core fibers are rapidly approaching their physical capacity limits. CICT, a state-owned enterprise, says its technology acts as an expanded information highway capable of instantly handling the massive data interactions required for AI training.
Engineering the multi-lane highway
To bypass current bottlenecks, the transmission record relied on two major innovations: a 24-core fiber and multi-band transmission.
A multi-core fiber integrates multiple independent light-transmitting cores into a single glass casing. The company likens its 24-core fiber to expanding a single-lane road into a 24-lane highway, multiplying capacity without taking up extra physical space.
Furthermore, the system utilized the S, C, and L bands — which stand for Short, Conventional, and Long wavelength optical bands. While traditional optical communication primarily relies on the Conventional C band, opening up the S and L bands is like adding two layers of elevated expressways to the existing road. This allows data to travel across a massive 19.65-terahertz total spectral bandwidth.
The company says this was not merely a laboratory simulation. The system relied on CICT’s self-developed, commercial-ready S+C+L integrated 400G coherent optical modules, marking a highly practical technical path for future network deployments. Completed jointly with Pengcheng Laboratory and FiberHome Fujikura Optic Technology Co., a Sino-Japanese joint venture, the findings were accepted as a high-scoring paper at the Optical Fiber Communication Conference (OFC) 2026.
A big SOE and a broader vision
Headquartered in Wuhan, CICT was established in July 2018 through the merger of the Wuhan Research Institute of Posts and Telecommunications and the Telecom Science and Technology Research Institute. It’s not just a regular state-owned enterprise (SOE), but one of the 98 SOEs that is directly owned by China’s central government.
Earlier this month, CICT and its partners published a study in the journal Nature, detailing a “fiber-wireless convergence” system. By utilizing ultra-broadband optical modulators built entirely on domestic manufacturing platforms, the company says the system successfully bridged the bandwidth gap between optical fibers and 6G wireless networks.
These localized achievements build on a deep global legacy of optical communication. Since Dr. Charles Kao theorized fiber-optic data transmission in 1966, and American pioneers like Corning and Bell Labs launched the first commercial lines in the 1970s, optical fibers have become the backbone of the digital economy. Driven by AI, 5G, and the demands of remote working, the global optical fiber market was estimated to be worth $9 billion in 2025 and is projected to hit $21 billion by 2034, according to Fortune Business Insights.
Market impact and an infrastructure “super cycle”
The industry is now rushing to bring these multi-core innovations from the lab to the market. At the OFC 2026 exhibition in Los Angeles, industry leaders including Corning and Yangtze Optical Fibre and Cable showcased mature multi-core fiber products, proving that production and testing standards are quickly falling into place.
Rahul Puri, CEO of the telecom company STL, noted in a recent interview cited by Chinese financial news provider CLS that while mass adoption will take time, the industry’s progress is much faster than before. “Traditionally this might take a decade, but I feel this year is the year of multi-core fiber,” STL’s Chief Technology Officer Badri Gomatam added.
Market analysts observe that optical modules are no longer just basic components, but are now the core infrastructure of the AI era. With 2026 widely viewed as a breakout year for domestic computing power, CICT’s breakthrough in ultra-large capacity networks clears a critical transmission hurdle, potentially setting off an investment super cycle for high-end optical chips, materials, and modules.
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