Glass optical fibers (GOF) are transmission media for data communication. While the term optical fiber merely states that light is transmitted in an optical conductor, the term glass fiber refers to the fact that both the core glass and the cladding glass are made of quartz glass or silicon dioxide. These optical fibers are also referred to as Silica Clad Silica( SCS) or All Glass Fiber( AGF).
The glass fiber consists of a thin cylindrical fiber made of fused silica( SiO2), the core glass and the cladding glass around the core glass, which is also made of high purity fused silica. The glass fiber is protected by a coating over a thin layer of varnish a few micrometers thick. The diameter of the core glass is between 9 µm and 200 µm, depending on the type of fiber; the cladding glass diameter is around 50 µm to 150 µm. The protective coating has a thickness of 50 µm to 100 µm.
The infrared beam modulated with data information makes its way through the optical fiber by total reflection of the beam at the boundary layer between core glass and cladding glass, since both materials have different optical densities. The light beam can also follow fiber bends.
Advantages of optical fiber
Optical fibers are characterized by high bandwidth, low attenuation and relatively good resistance to passive and active attacks. These include in particular resistance to electromagnetic interference (interference fields from machines, switches, lightning, transmitters, etc.) and the effects of light. The data rates that can be transmitted are many times higher than with copper lines. In addition, because of their low attenuation, optical fibers can transmit data over much greater distances. For example, distances of up to 100 km can be bridged with monomode fibers, whereas copper cables bridge distances of only 1 to 2 km at identical transmission rates. The maximum data rates that can be transmitted also differ by several powers of ten.
For the sake of comparability, fiber optic cables are classified according to a standardized designation system. This system takes into account the area of application, the type of fiber, the outer jacket, the core and jacket diameter, and much more.