An optical fiber or optical fibre is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer excessively. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber lasers.
-from wikipedia
Optical fiber communication is the most popular and effective communication method nowadays. Although it has been developed for not a long time, its role and impact is very far-reaching, even can say rewrite the history of communication. Furthermore, its developing prospects are unlimited.
Normally, light doesn’t carry useful information. In order to make use of the propagation of light in optical fiber to carry information, there are three steps. The first step is putting the needed information into electric information by the sender, and then using modulator to convert electric information to the light from the laser beam. At the same time, make sure the strength of the light be affected by the size of the electric rate of amplitude, frequency, and then using the principle of total reflection of light to use optical fiber to transmit signal light. The second step is that in the process of transmission, the Repeaters must be used to repair and amplify the optical signal, that’s because the optical signal in the transmission process will produce attenuation and distortion due to loss and dispersion. Long-distance transmission should be equipped with Repeaters usually in order to amplify the optical signal and repair the distortion of the information. Finally, the process in the terminal is similar to the inverse process of sending end, that is, after receiving the optical signal by the detector, the signal will be converted into an electrical signal and then restore the original information.
Comparing to the traditional way of cable transmission, Optical fiber communication transmission has several advantages:
- Large communication capacity, long communication distance, high sensitivity, no noise interference
- sensitivity, no noise interference sensitivity, no noise interference
Small size, light weight, long life, inexpensive - Insulation, resistance to high pressure, high temperature, corrosion, strong adaptability
- High confidentiality
- The raw material is abundant and the price is low.
In the period of high-developed level, in order to improve the function of optical fiber communication, we should update the switching system function continuously and integrate the transmission and switching processes. If this technology can be improved, the transmission efficiency can be improved significantly, the tough problems can be solved, and the deep promotion and application of optical fiber can be provided with a solid foundation. The main direction of optical fiber transmission development is big-volume, broadband networks, and low-price of optical equipment.
In the context of large-scale application of information intelligence, Internet cloud and other technologies, it is essential to improve the efficiency of big data transmission. The improvement of fiber transmission function will greatly promote the application and promotion of communication technology, which is of great practical significance. To improve the function of optical fiber communication, it is necessary to work hard on the optical fiber transmission itself and improve the transmission broadband and efficiency. Secondly, we should improve the efficiency of optical fiber devices, especially the efficiency of converters and modems, and solve the bottleneck of photoelectric information conversion. Optical fiber communication has a broad prospect and plays an irreplaceable role in promoting the development of science and technology and improving the quality of human life. Therefore, optical fiber communication workers must make great efforts to constantly explore and study and promote the continuous innovation and development of optical fiber communication technology.
by 吴楚翘 2017200502001