China sets a record for data transmission by fiber optic cable

Chinese scientists on May 9 announced that they had broken the world record for single-mode multi-core fiber-optic data transmission capacity, reaching 4.1 Pbit/s with 19-core fiber.

The team set a record with a 19-core fiber optic cable. Photo: CFP

The National Key Laboratory of Optical Communication Technology and Networking of China Information and Communication Technology Corporation (CICT) previously set a world record in November last year with milestone 3, 03 Pbit/s. They use wavelength optical multiplexing (WDM)/space division multiplexing (SDM) combined with 19-core cable transmission, using 680 wavelength channels with 25 GHz span, 17 THz bandwidth. . The results of the study were then published in the journal IEEE Photonics Technology Letters.

About six months later, the lab itself broke the record and achieved a total transmission capacity of 4.1 Pbit/s, an increase of nearly 40% from last year's record. To create a new record, Xiao Xi, head of the lab, said the research and development team optimized and upgraded the optical right system structure and digital signal processing algorithm.

Maintaining a bandwidth of 17 THz with the S, C and L bands, the research team optimized some electro-optical devices in the system for spectroscopy in the ultra-wide optical domain, improving the performance of the transmission channel in low frequency regions. different frequency bands. At the same time, they also applied advanced algorithms to make the most of the transmission power of 680 wavelength channels in the S, C and L bands. Thereby, the researchers maximized the transmission power of each core and channel by adjusting the information entropy (a measure of how chaotic a signal is derived from a random event) of the signal.