Pub. 4 2014 Issue 2

17 MINING FOCUS Recycling industrial-related scrap metal is one of the things we do best! www.umw.com | 801.364.5679 Utah Metal Works, Inc. FIBER OPTICS continued on page 18 are combined into cables that can then be used to transfer digital data over long distances. In addition, fiber optic cables are used in medical imaging and in mechanical engineering when it is necessary to inspect mechanical welds in hard-to-reach spots, such as within airplanes, cars, rockets, and any other equipment that is suited to the use of cables in some way. The reason fiber optics became a popular choice for transmitting data has to do with its many benefits: • Miles of optical cable are cheaper, lighter, and take up less space. • The diameter of an optical fiber is small, which means more fibers can be bundled together. That means more data can be transmitted at the same time, which is useful when you are transmitting something such as many television channels. • There is less signal degradation with optical fiber, which in turn means the same data can be transmitted using less power. • Fiber optic cables are incredibly flexible, making them well-suited for use in digital cameras where flexibility is one of the main requirements. For example, they work well in medical imaging equipment such as bronchoscopes, endoscopes, and laparoscopes, and they can also be used to inspect sewer lines. When you look at the diagram for a fiber-optic cable, you can see three parts: a central core, a layer that is called the cladding, and then a buffer coating: • The central core is the part made of optical fibers. • The cladding is designed to reflect light back into the central core. • The buffer is designed to protect the central core from moisture or from anything that could damage it. Two commonly used kinds of optical fibers are single-mode fibers and multimode fibers: • Multimode fibers are larger. The diameter is much larger, about 62.5 microns, or 2.5 x 10-3 inches. They are used to transmit infrared light, which has a wavelength ranging between 850 and 1,300 nanometers. • Single-mode fibers are designed to carry infrared laser light. The core is small, about 9 microns in diameter, or 3.5 x 10-4 inches. It can be that small because the wavelengths it carries are also small, typically from 1,300 to 1,550 nanometers. No matter how you look at it, both kinds of fiber are still extremely small. For example, if you were measuring the