The microfiber is encapsulated in a plastic sheath that allows it to bend without breaking. Usually, one end of the fiber optic transmitters with leds (light emitting diode, LED) or a laser light pulse transmission to optical fiber, optical fiber receiver at the other end of the light sensors were used to detect pulse. In daily life, the transmission loss of light fiber is much lower than the loss of electricity in wire conduction, and fiber is used as long distance information transmission. Usually the two nouns of optical fiber and optical fiber are confused. Most fibers must be covered by several layers of protective structures before they are used. The coated cable is known as a cable.
The protective layer and insulation layer of the optical fiber can prevent the surrounding environment from harming the fiber, such as water, fire and electric shock. Optical cable is divided into: optical fiber, buffer layer and overburden. The fiber is similar to the coaxial cable, but there is no mesh shielding layer. The center is the glass core of light transmission. In multimode fiber, the diameter of the core is 50 mu m and 62.5 mu m, roughly equal to the thickness of human hair.
The diameter of single mode fiber core is 8 mu m ~ 10 mu m. The core is surrounded by a glass envelope with a lower refractive index than the core to keep the light in the core. Outside is a thin plastic coat to protect the envelope. The fibers are usually bunched and protected outside. The core is usually a small double-concentric cylinder made of quartz glass, which is brittle and brittle, so it needs a protective layer.