1.1 Optical fiber communication technology overview
The overall optical fiber communication system consists of a large number of optical fibers, the main production material for the glass, itself is an electrical insulator, without considering the grounding loop problem. Since the development of optical fiber communication technology, the technology has developed rapidly with good performance. Especially in the era of the current information explosion, the application of optical fiber communication technology has made a tremendous contribution to the development of the communications industry and even the social transformation.
1.2 characteristics of optical communications
1.2.1 broadband communications, high capacity
In the single-band optical fiber communication system, the optical fiber is usually affected by the terminal equipment and can not fully express the characteristics of the broadband. Through the optical fiber communication transmission technology, this defect can be solved perfectly. The broadband and high-capacity features of optical fiber communication are of great significance for the transmission of information and can meet the development needs of broadband integrated services in the future.
1.2.2 low loss, long relay distance
Compared with other transmission media, practical quartz optical fiber loss can be 0.2dB / km or less, far less than other media, even if the future application of non-quartz optical fiber, the damage value is also about 10-9dB / km. The low loss of optical fiber determines the long-distance relay distance for optical fiber communication. The actual construction process can greatly reduce the communication system cost and improve the stability and reliability of the system.
1.2.3 strong anti-jamming performance
The material made of optical fiber has the insulating property and is weakly interfered by thunder and lightning, ionosphere and the like, and can also resist the interference caused by industrial electric appliances such as electrification equipment and high-voltage equipment to some extent and can be used for parallel installation with high-voltage power transmission lines or Power conductor composite composite optical cable communication transmission. The good anti-interference performance of optical fiber determines that it can be widely used in military, electrical and other fields.
1.2.4 no crosstalk interference, confidentiality and strong
In the traditional communication transmission process, the information carried by the bearer can easily be stealed and leaked. Therefore, the information security of the traditional communication is less effective. The optical fiber communication transmission process, there is no interference, the information is difficult to leak from the optical fiber. Light waves in the corner, due to the bending radius is too small, easy to leak, but its intensity is also very weak. For this problem, can be coated with matting agent measures to eliminate, so as to achieve the confidentiality of information, but also to meet the shielding crosstalk interference problems.
1.2.5 fine diameter, small weight
Optical fiber core radius of about 0.1mm, 1% for single-tube coaxial cable. The characteristic of low diameter makes the whole transmission system occupy less space, save underground pipe resources and reduce the advantages of floor space. In addition, the optical fiber is a glass material, the weight is very light, the weight of the cable is also small, 1m single tube coaxial cable weighs 11kg, while the same capacity of the cable is only 90g.
2, optical fiber communication technology development process
Development of optical fiber communication technology
Optical fiber communication technology research and development began in the fifties and sixties of the twentieth century, is in the third industrial revolution, the earliest developed fiber loss rate of 358 dB per kilometer. A few years later, scientists at the British Telecommunications Research Institute theoretically hypothesized that the minimum loss of optical fiber communication could be as low as 19 dB / km; subsequently, Japanese researchers successfully developed optical fiber with a loss rate of 100 dB / km, which is 50% less than the original product %the above. The UK subsequently developed quartz optical fiber with a loss of 20 decibels per kilometer. The latest research and development of germanium doped silica fiber loss of 0.2 dB per kilometer, is close to the theoretical loss limit.
From the middle of the 20th century, the optical fiber communication technology has undergone decades of research. Especially in the recent ten years, the technology has made great strides. Emerging technologies are emerging and the communication ability in the traditional sense is greatly improved. The technology A wider range of applications. Optical fiber communication technology has been gradually shifted from a single communications industry to a diversified level and has played an important role in all walks of life in society.
As a major change in the history of information and communication, optical fiber communication technology has been given a great deal of vitality since its birth. Decades of research and development, optical fiber communication technology has gone from the proposed theory to technical practice in the field of engineering, and then to the development of high-speed optical fiber communication. The development of optical fiber communication can be roughly divided into five stages: (1) (2) a multimode optical fiber with a wavelength of 1310 nm; (3) a 1310 nm single mode optical fiber; (4) a 1550 nm single mode optical fiber; and (5) a long distance transmission optical fiber communication technology.