Summary of Optical Fiber Communication Technology in China

The development of optical fiber communication depends on the progress of optical fiber communication technology. In recent years, the optical fiber communication technology has made great progress, and new technologies are constantly emerging, which greatly improves the communication ability and expands the application scope of optical fiber communication.

1. Development Status of Optical Fiber and Cable in China

1. 1 ordinary optical fiber

Ordinary single-mode fiber is the most commonly used fiber. With the development of optical communication system, the optical relay distance and single wavelength channel capacity increase, and the performance of G.652.A fiber may be further optimized, which indicates that the low attenuation coefficient in 1550rim region is not fully utilized, and the lowest attenuation coefficient and zero dispersion point of the fiber are not in the same region. The cut-off wavelength shifted single-mode fiber conforming to ITUTG.654 and dispersion shifted single-mode fiber conforming to G.653 have achieved such improvement.

1.2 core network optical cable

China's trunk lines (including national trunk lines, provincial trunk lines and regional trunk lines) have fully used optical cables, among which multimode optical fibers have been eliminated, and all of them use single-mode optical fibers, including G.652 optical fibers and G.655 optical fibers. G.653 optical fiber has been used in China, but it will not develop in the future. Because G.654 optical fiber can't greatly improve the capacity of optical fiber system, it has not been used in terrestrial optical cables in China. Trunk optical cable uses discrete optical fiber instead of optical fiber ribbon. Trunk optical cable is mainly used outdoors. In these optical cables, the tight-stranded and skeleton structure that has been used all the time has been stopped.

1.3 access network optical cable

In the access network, the optical cable has short distance, many branches and frequent insertion. In order to increase the network capacity, the number of optical fiber cores is usually increased. Especially in local pipelines, due to the limited inner diameter of pipelines, it is very important to increase the number of optical fiber cores, increase the optical fiber assembly density of optical cables and reduce the diameter and weight of optical cables. The access network adopts G.652 common single-mode fiber and G.652.C low water peak single-mode fiber. Low water peak single-mode fiber is suitable for dense wavelength division multiplexing, and it has been used in a small amount in China at present.

1.4 indoor optical cable

Indoor optical cables are usually used to transmit voice, data and video signals at the same time. And can also be use for telemetry and sensors. Indoor optical cables referred to in the International Electrotechnical Commission (IEC) optical cable classification should at least include indoor optical cables and optical cables for integrated wiring. The local telephone optical cable is laid in the local telephone office or other telecom room, closely and orderly, and its position is relatively fixed. The integrated wiring optical cable is placed in the user's room and mainly used by the user, so its vulnerability should be considered more strictly than that of the local telephone optical cable.

1.5 communication optical cable in power line

Optical fiber is dielectric, and optical cable can also be made of all dielectric and completely metal-free. This all-dielectric optical cable will be the most ideal communication line in power system. There are two kinds of all-dielectric optical cables for laying power lines: all-dielectric self-supporting (ADS) structure and winding structure for overhead ground wires. ADS optical cable has been widely used in the transformation of transmission system in China because of its independent deployment and wide application range. China has been able to produce a variety of ADS optical cables to meet the market demand. However, in terms of product structure and performance, such as the structure of large optical cable, creep and arc resistance of optical cable, etc. Need to be further improved. ADS optical cable is in great demand in China recently, and it is a popular product at present.

2. Development trend of optical fiber communication technology

For optical fiber communication, ultra-high speed, ultra-large capacity and ultra-long distance transmission have always been the goal that people pursue, and all-optical network is also the dream that people pursue unremittingly.

2. 1 ultra-large-capacity and ultra-long-distance transmission technology wavelength division multiplexing technology greatly improves the transmission capacity of optical fiber transmission systems and has broad application prospects in future cross-sea optical transmission systems. In recent years, wavelength division multiplexing (WDM) systems have developed rapidly. At present, 1.6Tbit/ WDM system has been widely used in business, and the all-optical transmission distance is also greatly expanded. Another way to improve transmission capacity is to adopt optical time division multiplexing (OTDM) technology. Unlike WDM, which improves the transmission capacity by increasing the number of channels transmitted by a single fiber, OTDM technology improves the transmission capacity by increasing the single channel rate, and its highest single channel rate reaches 640 Gbit/s.

After all, only relying on OTDM and WDM to improve the capacity of optical communication system is limited, and multiple OTDM signals can be wavelength division multiplexed, thus greatly improving the transmission capacity. Polarization multiplexing (PDM) technology can obviously weaken the interaction between adjacent channels. Because the space occupied by return-to-zero (RZ) coded signals in ultra-high-speed communication systems is small, the requirements for dispersion management distribution are reduced, and RZ coding method has strong adaptability to fiber nonlinearity and polarization mode dispersion (PMD), so the current ultra-large capacity WDM/OTDM communication systems basically adopt RZ coding transmission method. The key technologies to be solved in WDM/OTDM hybrid transmission system are basically included in the key technologies of OTDM and WDM communication systems.

2.2 optical soliton communication

Optical soliton is a special ps-class ultrashort optical pulse. Because it is in the abnormal dispersion region of optical fiber, the group velocity dispersion and nonlinear effect reach a balance, so the waveform and velocity remain unchanged after long-distance transmission through optical fiber. Optical soliton communication uses optical soliton as carrier to realize long-distance lossless communication. In the case of zero bit error, information can be transmitted as far as Wan Li.

The future prospect of optical soliton technology is: using ultra-long distance high-speed communication, ultra-short pulse control technology in time domain and frequency domain, ultra-short pulse generation and application technology, the current rate will be increased from 10~20Gbit/s to above 100Gbit/s; In the aspect of increasing transmission distance, retiming, shaping and regeneration technologies are adopted to reduce ASE, and the transmission distance is increased to more than 100000km through optical filtering. In the aspect of high performance EDFA, it is to obtain low noise and high output EDFA. Of course, there are still many technical problems in actual optical soliton communication, but the breakthrough progress makes people believe that optical soliton communication has a bright development prospect in long-distance, high-speed and large-capacity all-optical communication, especially in submarine optical communication systems.

2.3 all-optical network

The future high-speed communication network will be all-optical network. All-optical network is the highest and most ideal stage in the development of optical fiber communication technology. The traditional optical network has realized all-optical between nodes, but the nodes of the network still use electrical equipment, which limits the further improvement of the total capacity of the current communication network trunk, so the real all-optical network has become a very important topic.

All-optical network uses optical nodes instead of electrical nodes, and the nodes are all-optical. Information is always transmitted and exchanged in the form of light. Switches do not process user information bit by bit, but decide routing according to its wavelength.

At present, the development of all-optical network is still in its infancy, but it has shown a good development prospect. From the development trend, it has become the inevitable trend of future optical communication development, the core of future information network, the highest level or even the ideal level of communication technology development to form a real optical network layer based on WDM technology and optical switching technology, establish a pure all-optical network and eliminate the electro-optical bottleneck.

label

As an important supporting platform of information technology, optical communication technology will play an important role in the future information society. Although it has experienced the "cold winter" of global optical communication, the optical communication market will still show an upward trend in the future. From the development trend of modern communication, optical fiber communication will also become the mainstream of future communication development. The real all-optical network era that people expect will come as scheduled in the near future.

Did you get a look at him? Optical fiber communication light source technology paper? People still see:

1. Optical Communication Technology Paper

2. Optical fiber technology papers

3. Paper on optical fiber sensing technology

4. Paper on Optical Communication Technology (2)

5. Power system optical fiber communication technology paper