Glossary of Fiber Optic Terms

Glossary Of Fiber Optic Terms Glossary Of Fiber Optic Terms

Here's an alphabetical glossary of fiber optic terms. You can search the list using the alphabetical index below.


Absorption: That portion of fiber optic attenuation resulting of conversion of optical power to heat.

Analog: Signals that are continually changing, as opposed to being digitally encoded.

Attenuation Coefficient: Characteristic of the attenuation of an optical fiber per unit length, in dB/km.

Attenuation: The reduction in optical power as it passes along a fiber, usually expressed in decibels (dB). See optical loss.

Attenuator: A device that reduces signal power in a fiber optic link by inducing loss.

Average power: The average over time of a modulated signal.


Back reflection, optical return loss: Light reflected from the cleaved or polished end of a fiber caused by the difference of refractive indices of air and glass. Typically 4% of the incident light. Expressed in dB relative to incident power.

Backscattering: The scattering of light in a fiber back toward the source, used to make OTDR measurements. Bandwidth: The range of signal frequencies or bit rate within which a fiber optic component, link or network will operate.

Bending loss, microbending loss: Loss in fiber caused by stress on the fiber bent around a restrictive radius. Bit-error rate (BER): The fraction of data bits transmitted that are received in error.

Bit: An electrical or optical pulse that carries information.

Buffer: A protective coating applied directly on the fiber.


Cable: One or more fibers enclosed in protective coverings and strength members.

Cable Plant, Fiber Optic: The combination of fiber optic cable sections, connectors and splices forming the optical path between two terminal devices.