Optical fiber, referred to as fiber optics, is an optical fiber to achieve the principle of total reflection of light in glass or plastic fibers made of transmission of light-conducting tools. Fiber optic cable is a certain number of optical fibers in accordance with a certain way to form the core of the cable, the outer jacket, and in some cases, the outer jacket, to achieve the transmission of optical signals of a communication line.
Optical fiber, referred to as fiber optics, is an optical fiber to achieve the principle of total reflection of light in the fiber made of glass or plastic transmission of light-conducting tools. The microscopic fiber encapsulates a bundle of fibers in a plastic sheath that allows it to be bent without breaking. Typically a transmitting device at one end of the fiber uses a light-emitting diode or a beam of laser light to transmit pulses of light into the fiber, and a receiving device at the other end of the fiber detects the pulses using a photosensitive component. The cable containing the optical fiber is called a fiber optic cable. The use of optical fibers as a means of transmitting information over long distances was prompted by the fact that the transmission losses of light in optical fibers are much lower than those of electricity conducted through wires, and even more so by the fact that the main raw material for production is silicon, which is extremely abundant and easier to mine, and therefore cheaper. With the price of optical fiber further reduced, optical fiber is also used for medical and recreational purposes.
Optical fibers are divided into two main categories, gradient and mutant fibers. The former has a gradual change in refractive index while the latter has a mutation in refractive index. It is also divided into single-mode fiber and multi-mode fiber. In recent years, there are new photonic crystal fibers have been introduced.
Optical fiber is a double structure, the core part of the high refractive index glass, the surface part of the low refractive index of glass or plastic, light in the core part of the transmission, and in the junction of the surface layer of the total reflection, along the "zig-zag" shape forward transmission. This fiber is slightly thicker than a hair, such a thin fiber to have a refractive index of very different double structure distribution, is a very amazing technology. Scientists from various countries after many years of efforts to create a method of internal attachment, MCVD method, VAD method, etc., made of ultra-high purity quartz glass, made of optical fiber transmission of light efficiency has improved very significantly. Now the better optical fiber, its light transmission loss per kilometer is only zero point two decibels; that is to say, after spreading a kilometer loss of only 4.5%.