The three fiber optic cables differ in attenuation. Attenuation is mainly caused by two physical effects: absorption and scattering. Absorption removes the signal energy from the interaction between the propagating light (photons) and the core molecule. Scattering redirects light from the core to the cladding. When quantifying the attenuation of a fiber optic cable, it is used to operate at a specific wavelength of light (window) and minimize it at that wavelength. The most common peak wavelengths are 780 nm, 850 nm, 1310 nm, 1550 nm and 1625 nm. The 850 nm region is called the first window (it was originally used because it supported the original LED and detector technology). The 1310 nm area is called the second window, and the 1550 nm area is called the third window.
glass fiber optic cable
Glass fiber optic cables have the lowest attenuation. Pure glass fiber optic cables have a glass core and a glass cladding. This cable type is by far the most widely used. It is the most popular of the chain installers and the type of cable with which installers have the most experience. The glass used in fiber optic cables is ultra-pure, ultra-clear, silica or fused silica. During the manufacture of glass fiber optic cables, impurities are intentionally added to pure glass to obtain the desired refractive index needed to guide light. Add germanium, titanium or phosphorous to increase the refractive index. Add boron or fluorine to lower the refractive index. Other impurities may remain in the glass cable after manufacture.
plastic optical cable
Of the three types of fiber optic cables, plastic fiber optic cables have the highest attenuation. Plastic optical cables have a plastic core and cladding. This fiber optic cable is thick. Typical sizes are 480/500, 735/750 and 980/1000. The core typically consists of polymethyl methacrylate (PMMA) coated with a fluoropolymer. Plastic fiber optic cables are mainly used in the automotive industry. The higher attenuation relative to glass may not be a serious obstacle, given that short fiber optic cables are often required in data networks. When network designers are faced with budget decisions, the cost advantages of plastic fiber optic cables intrigue them. Plastic optical cables do have flammability issues. As such, it may not be suitable for some environments and care must be taken when running through air ducts. Otherwise, plastic fibers are considered to be very strong, have a small bend radius, and are able to withstand abuse.
Plastic-coated silica (PCS) cable
The attenuation of PCS cable is between glass and plastic. PCS cables have a glass core, usually glass silicon, and a cladding of plastic, usually a lower refractive index silicone elastomer. PCS fabricated with a silicone elastomer coating suffers from three major drawbacks. First, it has considerable plasticity, which makes the application of the connector difficult. Secondly, bonding is impossible. Third, it is practically insoluble in organic solvents. These three factors make this type of fiber optic cable particularly unpopular with link installers. However, some improvements have been made in recent years.
Fiber-to-the-home networks have increased the speed of connections available to homes, apartment buildings and businesses compared to the technology now in use in most places. A fiber-to-the-home network is the installation and use of fiber optics from a central point called an access node to individual buildings. The link between the user and the access node is realized through the fiber jumper. Loose tubes and tightly buffered fiber optic cables are often used for high-speed signal transmission, capable of supporting outdoor or indoor environments. Is there a cost-effective solution to support both indoor and outdoor environments in an FTTH network? To address this issue, we present the construction and comparison of loose-pack and tight-pack cables.
