Fiber Optics Explained Fiber Glossary

Fiber Optics Glossary


Absorption- signal loss created by light energy turning into heat.

Aramid Yarn- a protective woven strength member, usually made of Kevlar™.

Attenuation- the loss of optical power, expressed in dB (decibel) or dB/km.

Bandwidth- the information carrying capacity of a signal.

dB- a decibel.

dBm- decibels relative to one milliwatt.

Dielectric- a nonconductive medium.

Electromagnetic Interference (EMI)- the frequency spectrum of electromagnetic radiation that extends from subsonic frequency to X-rays.

Endface- the surface area of the fiber optic ferrule where the optical fiber is centered and polished.   

Factory Polishes- endfaces expertly polished during the manufacturing process. These polishes are known as PC (Physical Contact), SPC (Super Physical Contact), UPC (Ultra Physical Contact), and APC (Angled Physical Contact).

Ferrule- housing, alignment, and mating sleeve of fiber end.

Innerduct- pathway within a duct designed to facilitate later cable placement.

Laser- a coherent source of light with a narrow spectral width.

Light-Emitting Diode- a semiconductor device that emits incoherent light.

Lashing Wire- is a specially-made kind of wire used to attach one cable to another, a technique used in fiber optics to use the tensile strength of another, already routed cable to support the fiber optic cable. Fiber optic cables are most often lashed to telephone or power cables in aerial installations.

Micron- one millionth of one meter

Modulation- the coding of information onto a carrier frequency, including on/off light source digital coding.

Multiplexer (Mux)- a device which combines two or more separate signals for transmission through a single fiber.

Nanometer (nm)- One billionth of a meter. Most common unit of measurement for light.

Patchcord -  a fixed length of cable with connectors on both ends. Sometimes referred to as a cable assembly, patch cable, or jumper.

Plenum - the open space in buildings, above dropped ceilings and below raised floors, used for air circulation.

Plenum Rating - a fire-safety rating rewarded to cables that have passed fire-safety tests as outlined by the National Fire Protection Association.

Pulling Eyes (PVC and PE)- pulling eyes and eye sleeves are devices used to assist in pulling cable through ducts and innerducts.

Receiver- an electronic unit that translates optical signal to electrical/binary signal.

Refraction Index- the ratio of light velocity in a vacuum to its velocity in the transmitting medium.

Scattering- signal losses caused by undissolved particles and boundary roughness in fiber.

Splitter- a fiber device that optically splits signals.  

Total Internal Reflection- a phenomena occurring in an environment in which all surfaces have an index of refraction that ensures all light energy within that environment is not refracted, but reflected and contained in that internal space continually.

Transceiver- an optical device that serves as both transmitter and receiver.

Transmitter- an electronic unit that converts an electrical/binary signal to an optical signal using LEDs or lasers.

Wavelength- the optical term for frequency. Fiber optic transmission systems typically operate at 850nm, 1300/1310nm, 1550nm, and 1625nm wavelengths.


Fiber Optic Cable Troubleshooting and Fault Locating Flow Chart

    Refer to this simple flow chart to determine possible problems in your fiber optics transmission system. The chart is designed to first eliminate transmission equipment errors/malfunctions, then isolating problems in physical plants. Please see that Rx stands for receiver.




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At Cables For Less we offer a variety of high quality Fiber Optic solutions at great prices!

Visit our Fiber Optics section and shop from our ever-growing selection of patch cables such as 62.5/125 or 50/125 Multimode, Singlemode with any combination of LC, SC, ST, FC, MTP / MPO and MTRJ connectors. Of course we also carry a complete line of OM1, OM2 as well as 10GB OM3 and OM4 up to 100 Meters  Don’t see the fiber cable you need pre-made? Not a problem with our custom calculator, which allows you to build your fiber to exact specification! See our assortment of pre-made and customizable patch panels, collection of fiber couplers and termination boxes. Don’t forget our networking converters and MTP/MPO trunks, cassettes, and fan-out kits we even carry fiber optic cleaning supplies