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Fiber Optics Cable FAQs
- What is multimode fiber cable, and how is it used?
- What is single-mode fiber cable?
- What makes up fiber optic cable?
- What are the standard connectors for fiber optic cable?
What is multimode fiber cable, and how is it used?
Multimode fiber cable is constructed with a large-diameter core, this allows multiple modes of propagation. Multimode utilizes several wavelengths of light funneled through its fiber core. The primary use is for voice and data applications. It is generally used by phone companies since a single multimode fiber cable can accommodate hundreds of conversations simultaneously.
What is single-mode fiber cable?
Single-mode fiber cable is constructed of a small core and only allows one mode of propagation. Allowing only a single wavelength of light to pass through the core prevents wavelengths of light from overlapping and distorting data. Single-mode gives 50 times more distance compared with multimode. Single-mode is generally used in 10-/100-Mbps networks that cover extended areas, such as cable television and campus backbone applications. With single-mode fiber strands full-duplex you get higher bandwidth, close to twice the throughput of multimode fiber cable.
What makes up fiber optic cable?
Fiber optic cable consists of a core, cladding, coating, strengthening fibers, and cable jacket.
Core This is the physical medium that transports optical data signals from an attached light source to a receiving device. The core is a single continuous strand of glass or plastic that's measured (in microns) by the size of its outer diameter. The larger the core, the more light the cable can carry. All fiber optic cable is sized according to its core diameter. The three sizes most commonly available are 50-, 62.5-, and 100-micron cable.
Cladding This is a thin layer that surrounds the fiber core and serves as a boundary that contains the light waves and causes the refraction, enabling data to travel throughout the length of the fiber segment.
Coating This is a layer of plastic that surrounds the core and cladding to reinforce the fiber core, help absorb shocks, and provide extra protection against excessive cable bends. These buffer coatings are measured in microns (µ) and can range from 250 µ to 900 µ.
Strengthening fibers These components help protect the core against crushing forces and excessive tension during installation. The materials can range from Kevlar® to wire strands to gel-filled sleeves.
Cable jacket This is the outer layer of any cable. Most fiber optic cables have an orange jacket, although some types have black or yellow jackets.
What are the standard connectors for fiber optic cable?
The ST® connector, which uses a bayonet locking system, is the most common connector. The ceramic ferrule ensures high performance.
The SC connector features a molded body and a push-pull locking system. It's ideal for office, CATV, and telephone applications.
The MT-RJ connector features an RJ latch similar to Category 5 patch cable and phone cords-installation is literally a snap.
The FDDI connector comes with a 2.5-mm ceramic free-floating ferrule that minimizes light loss. A fixed shroud surrounds the ferrule for protection.
