amr mohamed
Occupation: : 369 Date of Birth : 1994-09-29 Join Date : 2010-11-12 Age : 29
| Subject: Fiber Optic Thu 18 Nov 2010, 3:19 pm | |
| Fiber OpticOptical fiber is
A wire of pure glass is thin - paper such a human hair - carry digital information over long distances. install fiber-optic Stated that the optical fiber is a wire thin and long glass clean and arranged in bundles called optical cables (Optical Cables) for use in the transfer of light signals over large distances. If we look closer proximity to a fiber-optic we'll see it consists of the following parts: 1 - the heart or Pulp (Core): a center fabric (fiber) and the light travels through it. 2 - Cover (Cladding): an article of Foreign Affairs of the fabric that surrounds the heart and mission to reflect the light outward from the heart and return it to him. 3 - the cover of protection (Buffer Coating): It is a plastic cover, and its mission to protect fabric from light and moisture damage. hundreds of thousands of these optical fibers arranged in bundles in the form of optical fiber cable. 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-mode fiber (Single-Mode Fiber). and be the heart of a small diameter up to 9 microns, and transmits signals, infrared laser with a wavelength range between 1300 to 1550 nm. 2 - multimode fiber Study (Multi-Mode This is where the heart is the largest with a diameter of up to 62.5 microns, and to carry the signals and the transfer of infrared diameter which ranges between 850 to 1300 nm and outgoing electronic valves of emitting light (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 the transfer of light that can be seen only by long wavelength greater than 650 nanometers, a 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). And here you can wonder, how could these fibers be transferred Alduuamuallomat digital. How do fiber-optic
Suppose we want to send bundles of light rays through a path, so that we can draw the path of light through this as light travels through the straight lines. Problem that can Tsadvina is if this path contains a turning point, what can be done in such a situation? The solution is 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 of the turning points? In this case we need a mirror at every turn, and placed the mirror at an angle to allow light to return to the heart at each corner along the path. This is exactly what is happening inside the optical fiber. Valdu travel through the pulp (the path) with leaps regular cover (mirror) at the turning points according to the so-called reflection total internal (Total Internal Reflection), and because the atmosphere does not absorb any of the traffic signals mobile within 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 diluted when these signals depends on the degree of purity of the glass that made him fibers and also supports the wavelength of the light sent through it (for example, 850 nm weakened by between 60 to 75 percent per kilometer) and some fiber which weakens the signal by less (10% per km at 1550 nm wavelength). communication system over fiber Aldoiipetkon this system the following elements: the transmitter (Transmitter): The to receive and guide the device to the light source (LASER or LED) and run it on and off as the correct sequence, thus generating the traffic light. And the transmitter is close to the optical fiber may contain lenses (focused lens) in order to gather and focus light within the tissue Bwria photosynthesis. Laser light has more power than that possessed of light from the LED emitter, but is more sensitive to changes in temperature, it also more expensive. FTTH (Fiber Optics) an environment of communication between the sender and the receiver. A regeneration point (Optical Regenerator): we pointed out in the above to some loss in signal (Signal Loss) when the light travels inside the fiber for long distances - as is happening inside the submarine cables - and this reached a tonic and organs to regenerate the signal along the cable in order to enhance weak signals. And consists of the device from the optical fiber with special coverage inlaid (doping), and works this section of the fiber pump laser (pump); When you arrive weak signal to this section, the laser energy here to make molecules traffic light works as if they were the source of the laser, whereupon the firing signals light of new and strong, but the same characteristics as the reference vulnerable the next. This means that this device works as if he amplifier laser for the signal coming to it. receiver (Optical Receiver): takes the signal, optical digital, and to loose encrypted and sent as a signal power to the user, whether it a computer or TV cable or phone. It contains the receiver optical photocells (photocells) or Valves E-light (photodiode) in order to feel the notes the traffic light. Preference optical fiber (Advantages) Why Caused fiber optic technology revolution in the world of communication compared with the wiring other traditional - copper wires, for example?
Reason appears in the following points:
1. The 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 inside the cable bundle 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 are talking about cable television system. - It has less in the signal. - Carries light signals. Unlike the copper wires that carry electrical signals, optical signals do not overlap (interference) among them, which means phone calls or television reception clearer. - The ability of 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. In the absence of the passage of electric current in it, there is no risk of burning. - Lighter in weight (lightweight). Compared with copper wire. And occupy less space when you pass under the earth's surface. - Flexible (flexible). Because of the high flexibility and send and receive light, they are used in many of the cameras digital for the purposes of theorizing Medical (Medical Imaging), examine the work of welding inside the pipes and engines Mickey **** Yeh difficult to access in airplanes, cars and rockets, as used in the plumbing pipes and narrow scanned . - How to create a fiber optic? Already stated that the main material in manufacturing is the glass - which is the main source of sand for him - because of too many details in this issue brief, we shall see. Optical fiber industry
Requires passage through several stages:
At the outset the work cylinder glass by a process of sedimentation Bukhari chemical rate (Modified Chemical Vapor Deposition) is a complex process carried out under high temperature and conditions of special chemical, and is the interaction of chloride silicon Sicl4 and chloride Germanium Gecl4 bubbles with oxygen, to produce silicon oxide Sio2 and oxide germanium Geo2 which bring together and Ivaba inside the pipe to form a glass or material fiber. and then be withdrawn in the form of wires, high and long in machines like lathes (Lathe) and are private and very accurate, called Towers pull fiber (Fiber Drawing Tower) and is covered fiber with a layer of plastic to protect them . then be examined fiber from several aspects such as: tensile strength, regularity 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 their links to weak signal, and finally the conductivity under water .
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