Fiber Optics Essay, Research Paper

The world of fiber optic technology seems to be new. While in actuality it dates back to the 1800’s. It was primitive but it was a form of fiber optic. In this paper I will be telling you what a fiber optic cable is made of, how a fiber optic system works and a history of fiber optics from the 1800’s to today.

Lets take a look at the optical fibers, what these fiber do is carry the light which is transmitted to the destination. Now we will look at what a cable is made of. A cable is made up of five different sections. We will start in the middle and work our way out. At the middle of the cable is the core. The core is the light transmitting section of the fiber, and it is made of silica. The next layer of the fiber is the most important for the travel of light down the cable. It is the cladding. The cladding acts like a guide for the light waves. This is important because light moves in waves and will shoot out of the core. The cladding reflects the light back into the core. The cladding is made of pure silica. The middle layer of the cable is called the buffer. The buffer is a protective layer that is made of acrylic polymer and its only function is to protect the cladding and the core. As for the fourth layer, this layer is for installation purposes. It is called the strength member; its function is to add strength while the cable is being pulled. It needs this section because the core is very small and if it is broken the wire will be useless. The final section of the cable is the outer jacket typically consists of one or more layers of a polymer that protects against physical or environmental damage to the structure. There are also two different types of fiber optic cables. There are single-mode cables and multi-mode cables. A single-mode fiber has a smaller core than multimode fiber, allowing only one mode of light to propagate through the core. While a Multimode fiber has a much larger core than single-mode fiber, allowing hundreds of rays of light to pass through the fiber simultaneously. It might appear that multimode fibers have higher information carrying capacity than single-mode fibers, but the truth is that single-mode fibers retain the integrity of each light pulse over longer distances, allowing more information to be transmitted. This high bandwidth has made single-mode fiber the ideal transmission medium for many applications and multi-mode more applicable where transmission distances are less than two miles. Now that you know what the cable is made out of and what each section does, I will tell how a fiber optic system works and some advantages and disadvantages of a fiber optic system.

How does a simple fiber optical communication system work? Well it works by using converters. It goes like this, a signal is sent to the system when it reaches the system it is sent into a converter which changes the electrical signal to light pulses. Then it is sent down the fiber optic cable. The next step is that a light detector receives the light pulses and then it turns the light pulses back in to an electrical signal. Once it is back in to that form it is now ready to be received by a telephone or computer for its intended use. All of this seems good so why don’t more people or companies use this technology for everyday use? As this seems good it does have some disadvantages. The electrical to light conversion is very expensive, another reason its not used as often is that it does not repair easily. To fix a broken cable you need more then a pair of wire cutters and electrical tape. You need special connecters and tools as well as the knowledge to find and fix a problem with broken cable. It is also hard to install, the average guy can’t go out a put together a fiber optic communication system. The connectors are very had to use and require special tools. It may seem that there are a lot of disadvantages so why should anyone use this type of a system? This question is easy to answer. People like speed. Fiber optics have a huge bandwidth. A way to explain bandwidth is like this. Think of information as a car. You have a big car and you want to put it into a garage. Bandwidth is the garage. If you have a small garage you will have a hard time getting your car inside of it. Fiber optics is like having a huge garage where you could fit ten of your cars and you don’t have to slow down for anything. The more bandwidth also means greater capacity, which larger companies need. Another advantage is security, a fiber optic cable cannot be tapped because if the light connection is broken then the system won’t work and they will know that there is a problem with the system. Another advantage is that it is versatile. It can handle all kinds of media data, voice and video. It can do all of those things that copper wire can do only it is hundreds of times faster then a copper wire.

Now we will move on to some history of optical communication. The person who first invented an optical telephone was Alexander Graham Bell he invented it in 1880. He called it the Photophone. He found that his earlier invention the telephone was much more reliable. How did Photophone work? The Photophone worked by using the suns light. He focused the light on a mirror and attached the mirror to a device that when he spoke shook the mirror. On the other end of his Photophone was another mirror that received the light and reflected the light to a device that decoded it and made sound. This is almost exactly how a fiber optic system works today. Except now we use fibers to send the light and don’t rely on the sun for the light. Bell scraped this invention because he found that it depended on too much. If there was bad weather the Photophone tended to be unreliable. So now that the technology to transmit information by the use of lights the next problem is to find a better medium to send the light beam. Swiss Physicist Daniel Collodon and French Physicist Jacques Babinet did some of the first experiments. These two men showed that light could move along jets of water in the 1840’s. 14 years after these men did showed that light could move through a jet of water another scientist named John Tyndall popularized the concept in his demonstration that had 2 tanks of water. He had a jet of water jumping from one tank to another and it was illuminated by light. Optical fibers went a step further. They are essentially transparent rods of glass or plastic stretched so they are long and flexible. During the 1920s, John Logie Baird in England and Clarence W. Hansell in the United States patented the idea of using arrays of hollow pipes or transparent rods to transmit images for television or facsimile systems. However, the first person known to have demonstrated image transmission through a bundle of optical fibers was Heinrich Lamm, than a medical student in Munich. His goal was to look inside inaccessible parts of the body, and in a 1930 paper he reported transmitting the image of a light bulb filament through a short bundle. However, the unclad fibers transmitted images poorly. All of this was just the beginning; people now realized the potential of light and fiber optic technology. The telecommunication industry was looking for greater bandwidth in the anticipation of greater television and telephone use. To do this they need to have higher frequencies and light seemed to be the cutting edge. They still had the problem of carrying the light from one place to another. So they tried to use lasers to connect one place to another. Just like Bells invention did. Just as Bell had found the atmosphere interfered with the transmission and made it unreliable. In September of 1970 the announcement was made that a single-mode fiber had been invented. The first-generation systems could transmit light several kilometers with out frequency repeaters. This brings us to the present day. Today the biggest challenge remaining for fiber optics is economic. Today telephone and cable television companies can cost-justify installing fiber links to remote sites serving tens to a few hundreds of customers. However, terminal equipment remains too expensive to justify installing fibers all the way to homes, at least for present services. Instead, cable and phone companies run twisted wire pairs or coaxial cables from optical network units to individual homes.

The world of fiber optics is a new technology but that is just because we didn’t have a good medium which to send the light wave to there destinations. That’s why the invention of single-mode fibers was huge in the world of fiber optics and communications. Eighty percent of the world’s long distance telephone calls go over a fiber optic cable. The bandwidth of fiber optics has also changed how the telecommunications industry has to do things. Before fiber optics they would need to run hundreds of wires. Now all they have to run is a single line to serve hundreds of people. As we depend more on technology it is good to know that fiber optics are one of the most reliable forms of communication.