Optical fiber cable stands as a communication cable consisting of tow or more glass or plastic optical fiber cores, which are located in the protective coating and are covered by plastic PVC external bushing. The transmission of signals along the internal optical fiber generally uses infrared rays. Communication cable is one of cables which is made up of more than one pair of wire insulated from each other and whose function is to transmit telephone, telegraph, facsimile documents, television and radio programs, data and other electrical signals. Compared with overhead open wire, communication cable has following advantages: large capacity of communication, high transmission stability, good confidentiality and less influenced by natural conditions and external interference.
The traditional communication cable adopts copper as the main transmission medium. Although copper is not a precious metal, its price fluctuates with the market. If the scale of the network construction is relatively large, we have to consider the engineering cost of the communication cable. This is the main drawback of the communication cable.
Furthermore, the communication cable can not adapt themselves to the transmission media of the future computer Internet. For example, Blu-ray DVD technology is already emerging. The high quality of video and audio picture makes the capacity of a film up to 50GByte, which is several dozen times larger than the capacity of the traditional DVD. The signal attenuation of communication cable is very serious. The relay equipment must be set up at a distance, which greatly increase the cost of using the Internet. In general, optical fiber has following advantages, such as light weight, low signal attenuation, free of relay equipment, wide transmission band, strong ability to resist electromagnetic interference, and so on.
The width of the band represents the size of the transmission capacity. The higher the carrier frequency, the wider the bandwidth of the signal that can be transmitted. In the VHF band, only 27 channels of TV programs and dozens of FM broadcasts can be transmitted, and millions of TV programs can be transmitted.
In the age of traditional communication cable, the loss of signal intensity per kilometer is more than 40dB when the signal is transmitted at 800MHz. As for the optical fiber, its loss of signal intensity is much smaller. If to transmit 1.31 micron light, its loss of signal intensity per kilometre is less than 0.35 dB, and if 1.55 micron light is transmitted, the loss per kilometre is even smaller, which can be less than 0.2 dB. This is 100 million times less than the loss of signal intensity of the coaxial cable, making the optical signal transmit further.
The speed of development of optical fiber technology is unimaginable. Its bandwidth for transmitting information is doubled every six months, while the expense is reduced by half. In the future, optical fiber transmission will be a majority of the market becoming the most important transmission means of the convergence of Internet, telecommunication network and radio and television network.
This article comes from Jiangsu Hansor Cable Technology Co., Ltd., http://www.jshansheng.com. Please reprint with the source indicated!