China's new breakthrough in optical communication research: one optical fiber can support 13.5 billion people talking at the same time

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The first 560Tb/s ultra-large capacity wavelength division multiplexing and space division multiplexing optical transmission system experiment in China can enable 6.75 billion pairs of people (13.5 billion people) to talk simultaneously on one optical fiber. This marks a new step for my country in the research field of "ultra-large capacity, ultra-long distance, and ultra-high speed" optical communication systems.

This experiment uses a single-mode seven-core optical fiber with independent intellectual property rights as the transmission medium. Unlike ordinary optical fibers, a single-mode seven-core optical fiber is equivalent to seven ordinary optical fibers combined into one. The person in charge of Wuhan University of Posts and Telecommunications said that if optical fiber information transmission is compared to a highway, ordinary optical fiber is a single lane, then the single-mode seven-core optical fiber is equivalent to seven parallel lanes, which can provide 7 times the transmission capacity of ordinary optical fiber. Through breakthroughs in process and technology, the single-mode seven-core optical fiber solves the problem of crosstalk between multi-core optical fibers, and the isolation reaches -70dB, reducing the interference and impact between "lanes" to the minimum.

While innovating the transmission medium, the system equipment used in this experiment used 16 single light sources. After the optical multi-carrier generation device, the single-core transmission capacity was 80Tbit/s, and the total system transmission capacity reached 560Tbit/s. It is reported that after the expert group's test and verification, the "560Tbit/s ultra-large capacity single-mode multi-core optical fiber transmission system" achieved this time is the first in China and has reached the international advanced level.

With the rapid rise of mobile Internet, cloud computing, big data, and Internet of Things applications, the surge in traffic has brought huge challenges to information and communication networks. Solving the problem of "explosive growth" of network data flow is becoming a competitive high ground in the global information and communication field. As a core R&D base in my country's optical communication field, Wuhan University of Posts and Telecommunications has made major scientific and technological breakthroughs in the field of "ultra-large capacity, ultra-high speed, and ultra-long distance" optical communication transmission in recent years. In 2014, the first experiment of 100.3Tb/s capacity transmission in the C+L band of an ordinary standard single-mode optical fiber was realized. In 2015, the transmission capacity exceeded 200Tb/s. In the same year, the commercial practice of the "three super" technology was successful.