OPTICAL FIBER

OPTICAL FIBER : IS A FIBER MADE OF PURE GLASS, CAN BE LONG AND HIGH, NOT EXCEEDING A THICKNESS OF THICK HAIR. BRINGS TOGETHER MANY OF THESE FIBERS IN BUNDLES IN OPTICAL CABLES, AND USED TO TRANSPORT OPTICAL SIGNALS OVER LONG DISTANCES TOO

Contents1 - Fiber optic components2 - divisions of fiber-optic3 - advantages of optical fiber4 - Applications

Fiber optic componentsOptical Fiber: It consists of two canisters Tada center called the first heart-Core is surrounded by the other drum is called the cover Cladding and then the protective cover Buffer Coating and outer casing of the cable (jacket)1- Core :It is a high-glass (cylinder) where the light is transmitted and is made from silica grafted (Paljrmanyum for example, Ge-silica)2- Cladding : Article bush meat takes the glass (Other Surrounding cylinder) is working on keeping the light in the center of the optical fiber is made from silica, the spectrum so that the refractive index of the heart larger than the refractive index of the cover, which is the condition required to obtain the total internal reflection3- Buffer coating : Plastic cover protects the optical fiber from moisture or protect it from damage and breakageHundreds or perhaps thousands of these optical fibers are lined up in a package together to be a light cord, which protects the outer casing so-called jacket

Divisions of the optical fiber :1- single mode fiber : Signals transmitted through optical layout of a uniform pattern in all fiber optical fiber package is used in telephone networks and cable television. This type of fiber is characterized by small radius of the heart where the glass up to about micron 9 and pass through a laser beam of infrared wavelength of 1.3-1.55 nm.

2- multi -mode fibers : And are moved by many of the patterns of optical signals through a single optical fiber, which makes better use of computer networks. This type of fiber-half the diameter of the largest in terms of up to 62.5 micron and transmitted through the infrared .

Advantages of optical fiber : 1. more capable of carrying information because of the highest fiber-optic wires regular, it can be a large number of them inside a package which increases the number of telephone lines or the number of channels of television broadcasting in one rope. Enough to know that the bandwidth of optical fibers up to 50THZ while larger bandwidth needs of broadcast television does not exceed 6Mh12. slimmer as the radius is less than the radius of the traditional copper wires for example, can replace the copper wire diameter of 7.62 cm from the latest fiber-optic diameter does not exceed 0.635 cm and this is especially important when extending the wires underground.3. lighter and can replace the copper wires and weighing 94.5 kilograms of another optical fiber weighs only 3.6 kg..

4. has less of signals sent 5. crosstalk can not be sent through

the fiber in the rope adjacent one which ensures the clarity of the transmitted signal, whether a telephone conversation or TV broadcast. It is also not subject to electromagnetic interference, which makes the transmitted signal as confidential, which is of particular importance for military purposes

6. non-flammable, which reduces the risk of fire7. require less energy in the generator because the loss during the delivery process a little

 Because of these advantages, the optical fiber entered in many industries, particularly telecommunications and computer networks. Also used in medical imaging as well as different kinds of Kmjdzisat high quality of the change in temperature and pressure, including its applications in exploration in the ground. There are different types of modern fiber optic recently discovered called Photonic crystal fiber, because it is made of Photonic crystals characterized by the transfer of light in which the lowest loss ..

1. evidence of movement at very high speeds, reaching more than 100 / Mega Byte Yalthanip

 Applications:1. in the medical field, where the vision of the stomach and other ones.2. in the field of communications. A broader area, which includes dozens of applications such as communications applications and television stations and others.3. in the field of genetic engineering, where the genetic code can be disassembled and the prevention of genetic diseases such as diabetes, Down syndrome, anemia 

Optical fiber communication :Optical fiber can be used as a medium for telecommunication and networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables. This allows long distances to be spanned with few repeaters. Additionally, the per-channel light signals propagating in the fiber have been modulated at rates as high as 111 gigabits per second by NTT,although 10 or 40 Gbit/s is typical in deployed systems

Each fiber can carry many independent channels, each using a different wavelength of light (wavelength-division multiplexing (WDM)). The net data rate (data rate without overhead bytes) per fiber is the per-channel data rate reduced by the FEC overhead, multiplied by the number of channels (usually up to eighty in commercial dense WDM systems as of 2008[update]). The current laboratory fiber optic data rate record, held by Bell Labs in Villarceaux, France, is multiplexing 155 channels, each carrying 100 Gbit/s over a 7000 km fiber. Nippon Telegraph and Telephone Corporation have also managed 69.1 Tbit/s over a single 240 km fiber (multiplexing 432 channels, equating to 171 Gbit/s per channel). Bell Labs also broke a 100 Petabit per second kilometer barrier (15.5 Tbit/s over a single 7000 km fiber).