An optical fiber or optical fibre can be a flexible, FTTH drop cable production line produced by drawing glass (silica) or plastic into a diameter slightly thicker compared to a human hair. Optical fibers are employed most often as a way to send out light involving the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and also at higher bandwidths (data rates) than wire cables. Fibers are being used as an alternative to metal wires because signals travel along them with lesser amounts of loss; furthermore, fibers can also be immune to electromagnetic interference, a problem from which metal wires suffer excessively. Fibers can also be employed for illumination, and are covered with bundles so they may be used to carry images, thus allowing viewing in confined spaces, as when it comes to a fiberscope. Specially engineered fibers may also be employed for a number of other applications, a number of them being fiber optic sensors and fiber lasers.
Optical fibers typically incorporate a transparent core surrounded by a transparent cladding material by using a lower index of refraction. Light is held in the core from the phenomenon of total internal reflection that causes the fiber to behave as being a waveguide. Fibers that support many propagation paths or transverse modes are classified as multi-mode fibers (MMF), while those that support just one mode are known as single-mode fibers (SMF). Multi-mode fibers generally have a wider core diameter and can be used for short-distance communication links as well as for applications where high power has to be transmitted. Single-mode fibers can be used as most communication links more than one thousand meters (3,300 ft).
Being able to join optical fibers with low loss is important in fiber optic communication. This is certainly more technical than joining electrical wire or cable and involves careful cleaving from the fibers, precise alignment of the fiber cores, and the coupling of the aligned cores. For applications that demand a permanent connection a fusion splice is normal. Within this technique, an electrical arc is used to melt the ends from the fibers together. Another common strategy is a mechanical splice, where ends of your fibers are held in contact by mechanical force. Temporary or semi-permanent connections are created through specialized optical fiber connectors.
The field of applied science and engineering worried about the design and implementation of optical fibers is recognized as fiber optics. The phrase was coined by Indian physicist Narinder Singh Kapany who is widely acknowledged since the father of fiber optics.
Daniel Colladon first described this “light fountain” or “light pipe” within an 1842 article titled In the reflections of the ray of light in a parabolic liquid stream. This kind of illustration comes from a later article by Colladon, in 1884.
Guiding of light by refraction, the key that makes fiber optics possible, was initially demonstrated by Daniel Colladon and Jacques Babinet in Paris in early 1840s. John Tyndall included a demonstration of it within his public lectures inside london, 12 years later. Tyndall also wrote concerning the property of total internal reflection in a introductory book regarding the nature of light in 1870:
As soon as the light passes from air into water, the refracted ray is bent for the perpendicular… When the ray passes from water to air it can be bent through the perpendicular… In the event the angle in which the ray in water encloses with all the perpendicular towards the surface be in excess of 48 degrees, the ray is not going to quit the water at all: it will likely be totally reflected on the surface…. The angle which marks the limit where total reflection begins is referred to as the limiting angle of the medium. For water this angle is 48°27′, for flint glass it is 38°41′, while for diamond it really is 23°42′.
Inside the late 19th and early 20th centuries, light was guided through bent glass rods to illuminate body cavities. Practical applications such as close internal illumination during dentistry appeared at the outset of the 20th century. Image transmission through tubes was demonstrated independently through the radio experimenter Clarence Hansell and also the television pioneer John Logie Baird in the 1920s. From the 1930s, Heinrich Lamm revealed that you could transmit images using a bundle of unclad optical fibers and used it for internal medical examinations, but his work was largely forgotten.
In 1953, Dutch scientist Bram van Heel first demonstrated image transmission through bundles of optical fibers using a transparent cladding. That same year, Harold Hopkins and Narinder Singh Kapany at Imperial College in London succeeded to make image-transmitting bundles with more than ten thousand fibers, and subsequently achieved image transmission by way of a 75 cm long bundle which combined several thousand fibers. Their article titled “A versatile fibrescope, using static scanning” was published in the journal Nature in 1954. The initial practical fiber optic semi-flexible gastroscope was patented by Basil Hirschowitz, C. Wilbur Peters, and Lawrence E. Curtiss, researchers on the University of Michigan, in 1956. During this process of developing the gastroscope, Curtiss produced the 1st glass-clad fibers; previous SZ stranding line had used air or impractical oils and waxes as the low-index cladding material. Many different other image transmission applications soon followed.
Kapany coined the word ‘fiber optics’ in an article in Scientific American in 1960, and wrote the initial book in regards to the new field.
The 1st working fiber-optical data transmission system was demonstrated by German physicist Manfred Börner at Telefunken Research Labs in Ulm in 1965, that has been then the initial patent application with this technology in 1966. NASA used fiber optics within the television cameras that had been delivered to the moon. During the time, the utilization in the cameras was classified confidential, and employees handling the cameras would have to be supervised by someone by having an appropriate security clearance.
Charles K. Kao and George A. Hockham of the British company Standard Telephones and Cables (STC) were the very first, in 1965, to promote the notion that the attenuation in optical fibers could possibly be reduced below 20 decibels per kilometer (dB/km), making fibers a practical communication medium.They proposed that the attenuation in fibers available at the time was brought on by impurities that might be removed, as opposed to by fundamental physical effects like scattering. They correctly and systematically theorized the lighting-loss properties for optical fiber, and revealed the proper material for such fibers – silica glass rich in purity. This discovery earned Kao the Nobel Prize in Physics in 2009.
The crucial attenuation limit of 20 dB/km was achieved in 1970 by researchers Robert D. Maurer, Donald Keck, Peter C. Schultz, and Frank Zimar doing work for American glass maker Corning Glass Works. They demonstrated a fiber with 17 dB/km attenuation by doping silica glass with titanium. A couple of years later they produced a fiber with only 4 dB/km attenuation using germanium dioxide because the core dopant. In 1981, General Electric produced fused quartz ingots that could be drawn into strands 25 miles (40 km) long.
Initially high-quality optical fibers could simply be manufactured at 2 meters per second. Chemical engineer Thomas Mensah joined Corning in 1983 and increased the rate of manufacture to in excess of 50 meters per second, making optical fiber cables cheaper than traditional copper ones. These innovations ushered from the era of optical dexopky04 telecommunication.
The Italian research center CSELT worked with Corning to develop practical optical fiber cables, causing the first metropolitan fiber optic cable being deployed in Torino in 1977. CSELT also developed an early technique for FTTH cable production line, called Springroove.
Attenuation in modern optical cables is way less than in electrical copper cables, creating long-haul fiber connections with repeater distances of 70-150 kilometers (43-93 mi). The erbium-doped fiber amplifier, which reduced the price of long-distance fiber systems by reducing or eliminating optical-electrical-optical repeaters, was co-created by teams led by David N. Payne of the University of Southampton and Emmanuel Desurvire at Bell Labs in 1986.
The emerging field of photonic crystals generated the development in 1991 of photonic-crystal fiber, which guides light by diffraction coming from a periodic structure, as opposed to by total internal reflection. The initial photonic crystal fibers became commercially obtainable in 2000. Photonic crystal fibers can transport higher power than conventional fibers and their wavelength-dependent properties might be manipulated to improve performance.