A wire of pure glass is thin - such paper human hair - carry digital information over long distances. Installation of fiber optic
We have stated that fiber-optic cables are thin and long line of pure glass and arranged in bundles called optical cables (Optical Cables) to be used in the transfer of light signals to great distances. If we take a closer look closely for a fiber-optic'll see it consists of the following parts:
1 -the heart or core (Core): a center fabric (fiber) and transmitted light through it
2 - Cover (Cladding): a substance foreign to the surrounding tissue and the heart and mission to reflect the light outside of the heart and return it to him.
3 - protective cover (Buffer Coating): It is a plastic cover, and its mission to protect the optical tissue damage and moisture. Hundreds of thousands of these optical fibers arranged in bundles in the form of optical cables. These packages are protected by the outer casing of the cable is called Cover (Jacket).
Optical fiber is divided into two basic types
1 - Single-fiber-type (Single-Mode Fiber). Heart and be of small diameter up to 9 microns, signals and transmits infrared laser with a wavelength range between 1300 to 1550 nm.
2 - fiber multi-mode (Multi-Mode Fiber).
This is where the heart is a larger diameter of up to 62.5 microns, and the carry and transmit signals by infrared diameter ranges between 850 to 1300 nm, and electronic valves made of light-emitting (Light Emitting Diodes LED). Some fibers can be made of plastic, but the basis of the (Core) with a diameter relatively large (1 mm), and suitable for light transmission, which can be seen just which wavelength greater than 650 nm, the light emitted from the LED mail (LED) does not fit this type of fiber for the transfer of laser light (emitted from a laser-firing). Here we can wonder how these fibers can be transferred Alduualmalomat digital.
How do optical fibers
Suppose we want to send bundles of light rays through a path, we can draw so that the light through this path as the light travels through the straight lines. Problem that can Tsadvina If this is the path contains a turning point, what can be done in such a situation? Solution to put a mirror at the point of inflexion (Bending) that in order to reflect light at this corner and return to the track. How if the path contains many turning points? In this case we need a mirror at every turn, and placed the mirror at an angle to allow the return of light to the heart at each corner along the route. This is exactly what is happening inside the optical fiber. Valdu travels through the core (path) with leaps regular cover (mirror) at the turning points by the so-called reversal total internal (Total Internal Reflection), and because the atmosphere does not absorb any of the signals of mobile inside the heart, the light signals can be transmitted over long distances . But some of these signals weaken within the fiber because of the purity of glass contamination for example, and the extent to which can be weakened when these signals depends on the degree of purity of the glass, which made him fibers and also supports the wavelength of the light sent through it (for example, 850 nm weakens by about 60 to 75 percent per kilometers) and some fibers weaken the signal by less (10% per km at 1550 nm wavelength).
Communication system via fiber-optic system consists of the following elements:
Transmitter (Transmitter): The reception and guidance of the light source device (LASER or LED) and run it on and off according to the correct sequence, and thus the optical signal is generated. And the transmitter is close to the optical fiber and may contain lenses (focused lens) in order to collect and focus light in the tissue Baraa photosynthesis. Laser light has a greater power than possessed by light from the LED emitter, but more sensitive to changes in temperature, as it is more expensive. Optical fiber (Fiber Optics) an environment of communication between sender and receiver. A regeneration signal (Optical Regenerator): we noted in the above cause some loss in signal (Signal Loss) when transmitted light within the fiber over long distances - as is happening inside the submarine cables - and this reached a tonic and organs regenerate the signal along the cable in order to enhance weak signals. And consists of the device from the optical fiber with a special coverage inlaid (doping), and works of this section of the fiber pump laser (pump); When you reach the weak signal to this section, the laser energy here makes the molecules traffic light work as if it were the source of the laser, whereupon the firing signals new light, strong, but with the same characteristics of the weak signal coming. This means that this device works as if it were a laser amplifier for the signal coming to it. The receiver (Optical Receiver): takes the signal optical digital and decoded, and sends electrical signal to the user was either a computer or cable TV or phone. The receiver contains optical light cells (photocells) an electronic or optical valves (photodiode) and notes to be sensitive to the traffic light. Advantage of optical fiber (Advantages) of what caused the optical fiber technology revolution in the world of communication, compared with other conventional wire - copper wire, for example?
Reason appears in the following points:
1. Relatively low cost.
2. Paper and the accuracy of the fiber. This leads to ..
- The ability to transport high (Higher carrying capacity) because of the paper fibers, many of which can be packed inside a cable with a diameter more than if the copper wires in the cable has the same diameter, which means a greater number of telephone lines connected or if the available TV channels We were talking about the cable TV system. - It has less in the signal. - Carries light signals. Unlike copper wires that carry electrical signals, optical signals do not overlap (interference) between them, which means phone calls or television reception clearer. - The ability of a lower transmission (Low Power). - Digital signals (Digital Signal). Optical fiber is designed primarily for the transfer of digital signals, and this is especially useful in computer networks or the Internet. - Non-flammable. Due to lack of passage of electric current in it, there is no risk of burning. - Lighter weight (lightweight). Compared with copper wire. And occupy less space when you pass beneath the surface of the earth. - Flexible (flexible). Because of their flexibility and high sending and receiving of the light they are used in many of the cameras digital for the purposes of theorizing Medical (Medical Imaging), inspection and the work of welding inside the pipes and engines Mickey **** Ye difficult to access in planes, cars, rockets, as used in plumbing pipes and narrow scanned . - How to create a fiber optic? Already mentioned that the main material in the manufacture of glass are - which is the primary source of sand for him - given the many details in this brief, we shall see. Industry traffic fiber optic require several stages:
At first the work cylinder glass by a process of sedimentation Bukhari chemical average (Modified Chemical Vapor Deposition) is a complex process carried out under high temperature and conditions of special chemical, and where the interaction of chloride silicon Sicl4 and chloride germanium Gecl4 bubbles with oxygen, to produce a silicon dioxide Sio2 and oxide, germanium Geo2 who Ijmaa Ivaba together and inside the pipes to form a glass fiber or material. And then is pulled in the form of wires, high and long in areas like lathes (Lathe) and be very private and accurate, called towers pull Fiber (Fiber Drawing Tower) and the fiber is covered with a layer of plastic to protect them. Then be examined fiber from several aspects such as: tensile strength, regularity of Qatar heart and the dimensions of the covers of protection, the vulnerability of the signal with the increase in length, the bandwidth (bandwidth), operating temperature and the humidity, and they relate to weak signal, and finally the conductivity under water.
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