With mobile Internet, cloud computing, big data The rapid development of technology, 400G will be the future of the next generation backbone network upgrade and new direction. In the realization of Optical fiberCommunication, an important issue is to reduce the loss of the fiber as far as possible, because the 400G long distance trunk transmission system of low loss optical fiber more demanding, ultra low loss fiber has become the best choice.
One,Reduce loss = save tens of millions of dollars
The fiber itself does not have high loss, high loss is caused by the impurities in the material, if the impurity is reduced, then the loss degree can also decrease. This theory is based on Dr. Kao, the Corelle company in 1970 successfully developed the loss of low loss silica fiber 17dB/km, the optical fiber communication from theory into reality.
Can reduce the loss of the transmission speed, speed increase, the transmission distance is lengthened, the state can reduce the use of a regeneration system of station, which is equivalent to save tens of millions of yuan. It can not only meet the load demand, but also to maximize the savings investment, therefore, experts and scholars and researchers are trying to reduce fiber loss.
At present, the attenuation value has dropped to 0.17~0.18dB/km ultra low loss optical fiber, greatly reduces the cost of construction, continue to be recognized. In 2011, the national grid in the power of heaven "Qinghai Tibet DC transmission project, the ultra low loss fiber used in the long span, not only reduces the difficulty and cost of operation and maintenance, improve the reliability of communication system, but also respond to the future network The need to upgrade.
Two, the two major roadblocks
Three major domestic carriers in developing FTTH And to the building, large-scale transformation of the fiber, they significantly increased the demand for fiber, which will give China domestic manufacturers to provide a huge market space. Also, the future backbone network, access network , Data center Such scenes have different requirement on fiber properties, ultra low loss fiber has coincided with the time.
However, in the development of ultra low loss fiber on the road still have two "stumbling block" to restrict the development of ultra low loss fiber attenuation, when the value reaches 0.18dB/km, it seems very difficult to break through. The high cost and difficult technical roadblocks are two ultra low loss fiber development.
1 high cost
Compared with the ordinary fiber and low loss optical fiber, ultra low loss fiber development is more difficult. Ultra low loss fiber profile structure, manufacturing process is completely different, R & D personnel to design section structure and the development of new manufacturing process requires a certain period of development, the cost is relatively high.
At present, the domestic manufacturers of the basic realization of the production of low loss optical fiber, some manufacturers also devote more manpower and material resources for R & D and production of ultra low loss fiber, but the domestic operators used demand is not obvious, operators need to consider the problem of benefit to national investment, cost assessment is one of the important measure of these all the common cause of the slow progress of research and development.
In addition, the deployment of ultra low loss fiber need adding large amounts of fluorine in the outer fiber medium, to ensure that the refractive index, while fluoride difficult to handle, and can cause environmental pollution, waste disposal is also difficult. Some experts have admitted that the domestic cable manufacturers can do some samples in the ultra low loss fiber, if mass production, domestic cable manufacturers in the cost control is also very difficult to achieve the foreign manufacturers mature ultra low loss fiber prices.
2 technical difficulties
stay 100G 400G network system, the deployment of low loss optical fiber can reduce the transmission cost of the total reduction of 10% (1 billion yuan), ultra low loss fiber can be reduced by 20% (2 billion 500 million yuan), in the face of such a big temptation, domestic manufacturers do still struggling, the main reason is that the ultra low loss fiber technology is difficult, yet the formation of a breakthrough.
It is reported that the two part of the scattering loss loss in fiber mainly from fiber materials and absorption loss. When the concentration of silica fiber material, containing two components are germanium oxide, light will be part of the light scattering power into the fiber outside, causing loss; similarly, when the fiber material and impurity absorption of light energy, they will put the light in the form of heat consumption in optical fiber.
our country Optical communication Industry chain is not perfect, lack of core technology, many products and the production process still needs to be imported, coupled with ultra low loss optical fiber cable manufacturing process is very difficult, the process compared with the traditional optical fiber changes greatly, and the need to repeatedly adjust, all of these will give the progress of ultra low loss fiber will bring lag.
Three, the conclusion
Now the domestic fiber manufacturers to produce low loss optical fiber based, taking into account the ultra low loss fiber industry is still not mature and high cost, so no large-scale deployment of ultra low loss fiber. The industry pointed out that currently on the market with real commercial ability of manufacturer is about two. The cost and technical problems are restricting the development of ultra low loss fiber, but the industry generally believe that the co operators and industry chain manufacturers, over the next 2-3 years, ultra low loss and large effective area of ultra low loss fiber will further mature.
