Network development puts new requirements on optical fiber
Next-generation networks (NGN) have sparked many opinions and debates. Some experts predict that no matter how the next-generation network develops, it will definitely reach three worlds, namely the IP world at the service level, the light world at the transmission level, and the wireless world at the access level. The next-generation transmission network requires higher speed and larger capacity. This is not the optical fiber network, but the development of high-speed backbone transmission also puts forward new requirements for optical fiber.
(1) Expand the transmission capacity of a single wavelength
At present, the transmission capacity of a single wavelength has reached 40 Gbit / s, and 160 Gbit / s research has begun. Transmission above 40Gbit / s will put forward certain requirements for the PMD of the optical fiber. At the ITU-T SG15 meeting in 2002, the United States has proposed a new fiber category (G.655.C) for the 40Gbit / s system, It is suggested that some problems in its PMD transmission be discussed in depth, maybe a special 40Gbit / s fiber type will appear in the near future.
(2) Achieve ultra-long distance transmission
Relayless transmission is ideal for backbone transmission networks. At present, some companies have been able to use dispersion homogeneous technology to achieve relayless transmission between 2000 and 5000km. Some companies are further improving the fiber optic index and using Raman optical amplification technology can extend the distance of optical transmission even more.
(3) Adapt to the application of DWDM technology
At present, 32 × 2.5Gbit / s DWDM systems have been used, and 64 × 2.5Gbit / s and 32 × 10Gbit / s systems have been developed and made good progress. The extensive use of DWDM systems has put forward higher requirements for the non-linear index of optical fibers. The ITU-T standard (G.650.2) for the nonlinear properties and test methods of optical fibers has also recently been completed. When the nonlinear test indicators for optical fibers are clear, corresponding indicators for the effective area of optical fibers will be proposed, especially for G. The non-linear characteristics of 655 fiber will require further improvement.
