Laser (Fiber Optics):

An acronym for "light amplification by stimulated emission of radiation," a device that generates intensified light, usually very directional and over a narrow range of wavelengths. Often a source of light in fiber optic systems.

Light (Fiber Optic):

An electromagnetic radiation in the wavelength range including infrared, visible, ultraviolet, and X rays, usually the range visible to the human eye, i.e., the energy that enables vision. Light travels in a vacuum at 300,000 km/sec. (186,281 miles per second).

Lightguide (Fiber Optic):

A fiber or a flexible bundle of fibers used to transmit light.

Loose Buffer (Fiber Optic):

Also called "loose tube," a protective tube loosely surrounding a cabled fiber, often filled with a gel.


Energy dissipated without accomplishing useful work, attenuation, usually expressed in dB.


A mechanical termination, usually crimped or soldered to the conductor, with provision for threading on to a terminal; hardware.