China Telecom sets world record in quantum‑classical co‑fiber transmission
China Telecom has announced a breakthrough in quantum communication, completing the world's first air‑core optical fiber experiment that transmits quantum and classical signals together over more than 100 kilometers. The test reached a distance of 101.6 km, establishing a new global benchmark and laying the foundation for large‑scale commercialization of quantum communication.
Traditional solid optical fibers face interference when quantum and classical signals are transmitted simultaneously, making it difficult to balance security and capacity. To solve this, China Telecom's research institute collaborated with China Telecom Quantum Group, Keda Shield Quantum, Changfei Optical Fiber, ZTE, and Beijing University of Posts and Telecommunications. The team relied on a large "cloud‑network integration" scientific device to develop new solutions.
Researchers introduced a spectrum collaborative allocation mechanism and a multi‑source crosstalk suppression strategy, enabling efficient and stable co‑fiber transmission. These innovations eliminated the long‑standing problem of mutual interference, giving the system combined advantages of low noise, high security, large capacity, and reduced complexity.
The experiment achieved four world‑leading indicators. Transmission distance reached 101.6 km, power supported 21 dBm high‑power transmission, capacity reached 37.6 Tbps, and the secure key rate remained stable at 5 kbps. These results meet the requirements for business applications and clear critical obstacles for implementing quantum communication technology.
China Telecom, founded in 2002 and headquartered in Beijing, is one of the largest telecommunications companies in China. It provides fixed‑line, mobile, broadband, and enterprise services, and is actively investing in next‑generation technologies such as quantum communication, cloud computing, and 5G infrastructure. The recent breakthrough highlights its role in advancing secure and scalable communication systems worldwide.
