Fiber Optic Structure Part 1

Fiber Optic Structure 

A Basic Structure of Fiber Optic Figure II-8 under the basic structure of an optical fiber, which consists of 3 parts: core (core), Cladding (skin), and coating (mantle) or buffer (protective). The core is a cylinder made from the stem material dielektrik (silica material (Sio2), usually given doping with germanium oxide (GeO2) Penta or phosphorus oxide (P2O5) for the international index biasnya) that do not use electricity, the core has a radius, the amount of about 8 - 200 μm and the index of refraction n1, the sekitar1, 5. Selubungi by the core layer of material, called a skin, made from materials dielektrik (without silica or slightly doping), the skin has a radius about 125 to 400 μm index bias, it n2, the amount slightly lower than n1.

Although light propagates along the fiber core without the skin layer of material, but the skin has several functions: 
- Reduce the loss of light from the core to the surrounding air. 
- Reduce hamburan loss on the surface of the nucleus. 
- Protecting the fibers from the absorption of surface contamination. 
- Increasing the mechanical strength. 

Two types of fiber cable: 
Surfergal Single-mode - USB single-mode fiber allows only one mode for the transmission of light through the fiber. (A mode is a light in the fiber at a certain angle reflection.) 
Surfergal Multimode - Multimode Fiber mode allows some light through the dirambatkan fiber cable. 
Figure below shows the single-mode fiber using a laser light source and multimode fiber using LED light source

Fourth - Sixth Generation

Fourth generation (from 1984) 
- Initiate research and development into a coherent system, modularity but not the intensity modulation frequency modulation, so that the signal is weak intensity, can still be detected, the distance that can be taken, also the transmission capacity, expand participate. 
- In 1984 capacity is equal to the capacity of direct detection system (intensity modulation). 
- Hampered its development since the technology tools and resources frequency modulation detection is still lagging behind. 

Fifth Generation (starting 1989) 
- Developed a brace that replaces the function of optical Repeater on the previous generation. 

- In the early development capacity transmission only achieved 400 Gb.km / s but a year later the transmission capacity is 50,000 penetrate Gb.km / s 

Sixth generation

- In 1988 Linn F. Mollenauer pioneered optical soliton communication system. Soliton waves are charging that consists of many components of long waves that are only slightly different, and also vary in intensity. 

- The length of soliton only 10-12 seconds and can be divided into several components near each other, so that the signals in the form of soliton is information that consists of several channels at once (Wavelength division multiplexing). 
- Eksprimen shows that the soliton can bring at least 5 channels, each carrying information with a rate of 5 Gb / s. The transmission capacity has reached 35,000 tested Gb.km / s. 
- How the system is the soliton Kerr effect, namely-ray diffraction long gelombangnya same will be spread with a different pace in a material intensity, if the price exceeds a limit. This effect is then 
menetralisir used to dispersi effects, so that the soliton is not the time to widen the Receiver. This is beneficial because the level of error is very small ditimbulkannya can even be ignored.

First - Third Generation

 Here are some historical stage of development of fiber optics technology: 
• First Generation (1970) 
- The system is simple and became the basis for the next generation system consists of:       ***Encoding: Change the input (eg voice) into electrical signals. 
***Transmitter: Changing electrical signals into light waves modulasi, in the form of LED with the wavelength 0.87 μm. 
***Silica Fiber: As the introduction to light waves. 
***Repeater: In light of the wave is weak on the road 
***Receiver: Change modulasi light waves into electrical signals, a photo-detector 
***decoding: Changing the signal into electrical ouput (eg voice) 
- Repeater work with the light waves into electrical signals and then strengthened in electronic and changed back into light waves.
 In 1978 transmission capacity can reach 10 Gb.km / s. 

• Second Generation (from 1981) 
- To reduce the effects dispersi, the size of the core fiber zooms. 
- Index of bias, leather-made sedekat proximity with the core index of refraction. 
- Using a diode laser, long waves that emanated 1.3 μm. 
- Transmission capacity to 100 Gb.km / s. 

•  Third Generation (1982 start) 
- The creation of silica fiber. 
- Creation chip diode laser berpanjang wave 1.55 μm. 
 Purity-silica material can be improved so that  transparent made for the long waves around 1.2 μm to 1.6 μm 
- Capacity transmitting a few hundred Gb.km / s.

The History of Fiber Optic Technology

The History of Fiber Optic Technology 

In the year 1880 Alexander Graham Bell to create a communication system called light photo-phone using the light from the sun that dipantulkan a mirror-termodulasi thin voice to bring the conversation, the recipient sun termodulasi about a photo-cell kondukting-selenium, which alter a the flow of electricity, a phone receiver complete system. Photophone never achieve commercial success, although the system is working quite well.

 The big breakthrough in technology to bring fiber-optic communication with the discovery of high-capacity laser in 1960, but in the key in the fiber system that is practical yet found an efficient fiber. New fiber in 1970 with the loss of low-developed communications and fiber optics to be practical (Fiber optics used as cylindrical wire in general, consists of a core fiber (core) that are wrapped by the skin (Cladding), and both protected by the protective jacket (buffer coating)). This happened only 100 years after John Tyndall, a fisikawan Great Britain, the Royal Society to demonstrate that light can be guided along the curve of water flow. Dipandunya light by a fiber optic and by the flow of water is from the same phenomenon that total namely internal Reflection.

Fiber optic technology is always faced with the problem of how to more information that can be taken, faster and more far longer with the level of error that  to a minimum. Information taken the form of digital signal, the transmission capacity used amount measured in 1 Gb.km / s, which means 1 billion bits per second can be delivered through a distance of 1 km.

to be  continues...