FOA CFOT Terms and Definitions A thru Z
Absorption - answer-Portion of fiber optic attenuation resulting from the conversion
of optical power to heat.
Analog - answer-Signals that are continually changing as opposed to being digitally
encoded.
Angled Physical Contact (APC) - answer-Technique involving polishing the end
surface of the fiber to a slight angle to prevent reflectance. Considered better than
convex polishing techniques (PC).
Attenuation / Attenuator - answer-Reduction in optical power as it passes along a
fiber is called ___________, usually expressed in dB. Devices that do this purposefully
are called _____________
Backscattering - answer-The scattering of light in a fiber back toward the source,
used to make OTDR measurements.
Bandwidth - answer-Range of signal frequencies or bit rate within which a fiber optic
component, link or network will operate. The maximum speed that data can be
transmitted over the link.
Bending Loss / Microbending Loss - answer-Loss in fiber caused by stress on the
fiber bet around a restrictive radius.
Bit - answer-An electrical or optical pulse that carries information.
Bit-Error Rate (BER) - answer-Fraction of data bits transmitted that are received in
error.
Buffer - answer-A protective coating applied directly on the fiber.
Chromatic Dispersion - answer-Temporal spreading of a pulse in an optical
waveguide caused by the wavelength dependence of the velocities of light.
Cladding - answer-Lower fractive index optical coating over the core of fiber that
"traps" light into the core.
Coarse Wavelength Division Multiplexing (CWDM) - answer-Use of lasers spaced
widely over the range of 1260nm to 1670 nm.
Connector - answer-A device that provides for a demountable connection between
two fibers (or fiber and active device). Also provides protection for the fiber.
Core - answer-The center of the optical fiber through which light is transmitted.
Coupler - answer-Device that splits or combines light from more than one fiber.
, Cutback Method - answer-Technique for measuring loss of bare fiber by comparing
the sources initial coupled power to the power measured at the end of a long length
of fiber.
Cutoff Wavelength - answer-The wavelength beyond which singlemode fiber only
supports one mode of propagation is called a what?
dBm - answer-Optical power referenced to 1 miliwatt.
Decibel (dB) - answer-Unit of measurement of optical power which indicates relative
power on a logarithmic scale. dB = 10 log
Detector - answer-Photodiode that converts optical signals into electrical signals.
Dispersion - answer-Temporal spreading of a pulse in an optical waveguide. May be
caused by modal or chromatic effects.
Distributed Feedback Laser (DFB) - answer-Used for high speed and long distance
transmitters.
Edge-emitting Diode (E-LED) - answer-An LED that emits from the edge of the
semiconductor chip, producing higher power and narrower spectral width.
End Finish - answer-Quality of the end surface of a fiber prepared for splicing or
terminated in a connector.
Equilibrium Modal Distribution (EMD) - answer-Steady state modal distribution in
multimode fiber, achieved some distance from the source, where the relative power
in the modes becomes stable with increasing distance.
ESCON - answer-IBM standard for connecting peripherals to a computer over fiber
optics.
Excess Loss - answer-Amount of light lost in a coupler, beyond what is typical in the
splitting to multiple output fibers.
Ferrule - answer-Precision tube which holds a fiber for alignment for
interconnection. Typically made from ceramics and is white in color.
Fiber Amplifier - answer-Uses erbium or other doped fibers and pump lasers to
increase signal output power without electronic conversion.
Fiber Identifier - answer-Device that clamps onto a fiber and couples light from the
fiber by bending, identifying the fiber (amongst others in a bundle, for example) by
detecting high speed traffic of an operating link or 2kHz tone injected by a test
source.
Fiber Optic Link - answer-Combination of transmitter, receiver and fiber optic cable
capable of transmitting data. May be analog or digital.
Absorption - answer-Portion of fiber optic attenuation resulting from the conversion
of optical power to heat.
Analog - answer-Signals that are continually changing as opposed to being digitally
encoded.
Angled Physical Contact (APC) - answer-Technique involving polishing the end
surface of the fiber to a slight angle to prevent reflectance. Considered better than
convex polishing techniques (PC).
Attenuation / Attenuator - answer-Reduction in optical power as it passes along a
fiber is called ___________, usually expressed in dB. Devices that do this purposefully
are called _____________
Backscattering - answer-The scattering of light in a fiber back toward the source,
used to make OTDR measurements.
Bandwidth - answer-Range of signal frequencies or bit rate within which a fiber optic
component, link or network will operate. The maximum speed that data can be
transmitted over the link.
Bending Loss / Microbending Loss - answer-Loss in fiber caused by stress on the
fiber bet around a restrictive radius.
Bit - answer-An electrical or optical pulse that carries information.
Bit-Error Rate (BER) - answer-Fraction of data bits transmitted that are received in
error.
Buffer - answer-A protective coating applied directly on the fiber.
Chromatic Dispersion - answer-Temporal spreading of a pulse in an optical
waveguide caused by the wavelength dependence of the velocities of light.
Cladding - answer-Lower fractive index optical coating over the core of fiber that
"traps" light into the core.
Coarse Wavelength Division Multiplexing (CWDM) - answer-Use of lasers spaced
widely over the range of 1260nm to 1670 nm.
Connector - answer-A device that provides for a demountable connection between
two fibers (or fiber and active device). Also provides protection for the fiber.
Core - answer-The center of the optical fiber through which light is transmitted.
Coupler - answer-Device that splits or combines light from more than one fiber.
, Cutback Method - answer-Technique for measuring loss of bare fiber by comparing
the sources initial coupled power to the power measured at the end of a long length
of fiber.
Cutoff Wavelength - answer-The wavelength beyond which singlemode fiber only
supports one mode of propagation is called a what?
dBm - answer-Optical power referenced to 1 miliwatt.
Decibel (dB) - answer-Unit of measurement of optical power which indicates relative
power on a logarithmic scale. dB = 10 log
Detector - answer-Photodiode that converts optical signals into electrical signals.
Dispersion - answer-Temporal spreading of a pulse in an optical waveguide. May be
caused by modal or chromatic effects.
Distributed Feedback Laser (DFB) - answer-Used for high speed and long distance
transmitters.
Edge-emitting Diode (E-LED) - answer-An LED that emits from the edge of the
semiconductor chip, producing higher power and narrower spectral width.
End Finish - answer-Quality of the end surface of a fiber prepared for splicing or
terminated in a connector.
Equilibrium Modal Distribution (EMD) - answer-Steady state modal distribution in
multimode fiber, achieved some distance from the source, where the relative power
in the modes becomes stable with increasing distance.
ESCON - answer-IBM standard for connecting peripherals to a computer over fiber
optics.
Excess Loss - answer-Amount of light lost in a coupler, beyond what is typical in the
splitting to multiple output fibers.
Ferrule - answer-Precision tube which holds a fiber for alignment for
interconnection. Typically made from ceramics and is white in color.
Fiber Amplifier - answer-Uses erbium or other doped fibers and pump lasers to
increase signal output power without electronic conversion.
Fiber Identifier - answer-Device that clamps onto a fiber and couples light from the
fiber by bending, identifying the fiber (amongst others in a bundle, for example) by
detecting high speed traffic of an operating link or 2kHz tone injected by a test
source.
Fiber Optic Link - answer-Combination of transmitter, receiver and fiber optic cable
capable of transmitting data. May be analog or digital.
