In the seventies, it became very fashionable to have a night light in the bedroom, which consists of stand hemispherical and protruding from it the beam waveguide.In the dark, this design dim light radiated in the form of small dots, burning at the tips of thin translucent fibers.This is really a beautiful thing was made from the waste products of a new kind of information the conductors.Name them - optic cables (aka - installer, ie fiber-optic communication lines).
The principle of fiber-optic
Every electrical conductor has a resistance not only active but also reactive (capacitive and inductive).These physical parameters are dependent on the diameter of the wire, its wave properties, and of course the length of the line connecting the sender signal receiving device.Particularly sensitive to resistive link high quality channels.Fiber-optic cable does not have this shortage, the loss of it is incomparably smaller than in normal conductors, because the data carrier is light energy.The principle of operation of the channel quite clear and simple.The input link signal is converted from electrical to optical.The output is its demodulation, and it enters the receiver-information device in the form of a conventional voltage pulses.
Advantages of fiber channel
addition to resistance to interference and attenuation, optical cables have other very significant advantages.When you send information through fiber channels it is much easier to keep it confidential, because it is almost impossible to secretly connect.Another advantage of this method of transmission is economic.Copper - an expensive metal and color, from the waveguide materials more affordable price.Optical cable is made from quartz or special polymer compositions (fluoro-aluminate, or fluoro-zirconate), which are also (the third dignity) is much lighter than metal wires that need to be also screened.
Disadvantages of optical communication
Yes, optical cables, like everything else in this world, is not without drawbacks.
First, to restore communication with open circuit is required to replace the entire damaged area, splicing waveguides can not be so seriously increases the cost of repairs.
Secondly, the construction works are too expensive.For their implementation need to precision machinery, and it is expensive.And skills required considerable, and they need and pay accordingly.
Third, to said signal converter input and output lines and connectors (devices that provide switching), very high requirements in terms of reliability, optical losses of accuracy.What quality is worth the money, no one to explain is not necessary.Contact
future
Still merits more.Optical cables can transmit a broadband signal, which significantly increases the speed of information exchange (measured in the terabits per second).When this attenuation is extremely small (at a wavelength of 1.55 microns, it is only 0.22 dB / km).In addition, the ability of the light waves move in opposite directions (with different polarization) in a conductor increases the possibility of VOLS.Their improvement continues.
