Glossary

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1000Base LX
The name for Gigabit Ethernet that is transmitted over fiber using long wave transmitters.
1000Base SX
The name for Gigabit Ethernet that is transmitted over fiber using short wave laser transmitters.
1000Base T
The name for Gigabit Ethernet transmitted over a twisted pair.
100Base FX
A 100 Mbps Ethernet system based on 4B/5B signal encoding that is transmitted over fiber optic cable.
100Base T
A term used for the entire 100 Mbps Fast Ethernet system, including both twisted-pair and fiber optic media types....
10Base F
A 10 Mbps Ethernet system based on Manchester signal encoding transmitted over fiber optic cable.
10Base T
A 10 Mbps Ethernet system based on Manchester signal encoding transmitted over Category 3 or higher twisted-pair cable.
10Base2
A 10 Mbps Ethernet system based on Manchester signal encoding transmitted over thin coaxial cable; also known as thinwire...
10Base5
A 10 Mbps Ethernet system based on Manchester signal encoding transmitted over thick coaxial cable; also known as thicknet....
10Gig Fiber Optic Patch Cord
A laser optimized fiber that supports 10 Gigabit per second transmission for distances of 300 meters or more and...
802.1
An IEEE working group for high-level interfaces, network management, inter-networking and other issues common across LAN technologies.
802.3
An IEEE working group for carrier-sense multiple access/carrier detect Local Area Networks.
802.3 Network
A 10 Mb/s CSMA/CD bus-based network; is commonly referred to as Ethernet.
802.5 Network
A token-passing ring network that operates at 4 Mb/s or 16 Mb/s.
8B10B Encoding
A signal modulation scheme in which eight bits are encoded in a 10-bit word to ensure that too many...
Abaxial Spherical Aberration
This type of aberration occurs when a patch of light is formed on points outside of the lens axis....
Abbe Condenser
This condenser consists of two lenses that collect and direct light onto a predetermined object. It can achieve high...
Abbe Constant
The ratio of an optical medium's refractivity to its dispersion. It is the reciprocal of dispersive power.
Abbe Illumination
A form of illumination where the source is imaged directly onto the object being viewed or projected. This requires...
Abbe Prism
A type of roof prism with perpendicular end faces that can invert an image when inserted between the object...
Abbe Refractometer
An optical instrument used to measure the of index of refraction of an unknown sample of optical glass. Designed...
Abbe Sine Condition
A condition that must be met by any spherically corrected lens if it is to be free from coma...
Abbe-Porro Prism
A compact version of the traditional Porro prism used in binoculars.
ABCD Matrix
Also known as a ray transfer matrix, this is a 2-by-2 matrix describing the effect of an optical element...
Aberration
A deviation from what is normal or expected. In optics, this could be a defect in a lens system...
Aberration Sensor
An optical instrument that can detect and measure aberrations via a knife-edge technique.
Ablation Threshold
An energy input level at which absorbed laser energy can break the bonds between molecules.
Ablative Photodecomposition
The process of pulsed ultraviolet radiation being absorbed by a material, leading to excitation within and between molecules. This...
Ablative Wall Flashlamp
A bright, short-lived source that occurs when low-pressure gas vaporizes material from the tube wall and leads to a...
Abney Effect
The hue shift that results when purity and saturation are varied.
Abrasion Mark
A mark on an optical surface produced by surfaces sliding against each other.
Abridged Spectrophotometer
An instrument that uses bandpass filters to measure transmission and reflection as a function of wavelength.
Absolute Refractive Index
The ratio of the speed of light in a vacuum to the speed of light in the medium.
Absorb
The mechanism by which materials transform incident energy into internal energy (typically heat).
Absorbance
A measure of a medium's ability to absorb radiation, often expressed as the reciprocal logarithm of transmittance.
Absorbing Wedge
A strip of glass with transmission that varies linearly with distance, due to varying absorption.
Absorptance
Ratio of the absorbed radiant flux to the incident flux.
Absorption
The portion of energy (light) that is attenuated during propagation via energy exchange in the material.
Absorption Band
A region of the spectrum in which the absorption coefficient reaches a maximum. Also a range of electromagnetic radiation...
Absorption Coefficient
The measure of how far a wavelength's light can travel before being absorbed. Also the measure of a gas's...
Absorption Hologram
A hologram that results from the light of an illuminating beam being absorbed in correspondence with recording exposure.
Absorption Index
The measure of attenuation caused by absorbed energy per unit of distance in an electromagnetic wave.
Absorption Lens
A lens that inhibits certain wavelengths from passing through it by absorbing them.
Absorption Line
The most narrow range of radiant energy wavelengths that can be absorbed.
Absorption Meter
An instrument that uses a light-sensitive detector to measure how much light is transmitted by a material.
Absorption Peak
In the field of spectroscopy, the maximum wavelength of radiation that can be absorbed by a sample.
Absorption Spectrophotometer
An optical instrument that measures the absorption spectra of different specimens.
Absorption Spectroscopy
The study of energy and wavelengths of radiation that atoms and molecules absorb under varying physical conditions.
Absorption Spectrum
Also referred to as the spectral window of absorption, this spectrum is formed by radiation that has been filtered...
Accelerated Aging
The operation of a sample population of the lasers for an extended period of time under harsher conditions then...
Acceptance Angle
The largest launch angle of incident light that can propogate down the fiber optic
Acceptance Cone
The largest launch angle of incident light that can propogate down the fiber optic. The 3D view of the...
Acceptance Pattern
A curve expressing an optical fiber's total transmitted power as a function of its launch angle at the input.
Acousto Optic Modulators
A device that uses an electrical drive signal to control the power, frequency, and spatial direction of a laser...
Acousto Optic Tunable Filter
AOTF is an optical filter that can be tuned by altering the refractive index using acoustic waves in the...
Acousto Optics
The study of interactions between sound waves and light waves. Sound waves can be made to modulate, deflect and...
Acoustophotorefractive Effect
A semipermanent change in the Index of Refraction that results from the interaction between high-intensity, short-lived lase pulses and...
Acrylate
A polymer material, made of salt from acrylic acid, used in optical fibers as a buffer coating or cladding,...
Active Area
The area of a detector, relative to the total area of the detector, that generates signal.
Active Branching Device
A device that converts an optical input into two or more optical outputs with gain or generation.
Active Device
A device that requires an energy source to operate and has an output of present and past input signals....
Active Port Diameter
The diameter of the area on a detector where light can be coupled to or from an optical fiber....
Adjustable Attenuator
An attenuator in which the level of attenuation can be changed using an internal adjustment. Also known as a...
Aging
The operation of a sample population of lasers for an extended period of time under specified conditions.
Aligned Bundle
An assembly of fibers that have the same coordinates at both ends of the bundle. Also called a coherent...
Alignment Laser
A laser, usually employing helium-neon or other gases as the active medium, used for alignment in industrial applications.
Alignment Sensitivity
A laser's sensitivity in regards to misalignment.
All Dieletric Cable
A cable made of dielectric materials that doesn't contain metal conductors, armor, or strength members.
All Silica Fiber
A fiber, also known as all-glass fiber, with a silica core and silica cladding.
All Solid State Lasers
A laser with a solid gain medium and pump source.
Alpha
A positive number that indicates the Core Refractive Index shape and ranges from one to infinity.
Ambient Temperature
The average temperature of the air that comes in contact with testing instruments.
Angle of Incidence
The angle between an incident ray and the line perpendicular to it.
Angle of Refraction
The angle composed of a refracted ray and surface line.
Angled Physical Contact
A fiber optic connector with the minimum possible back reflection due to a 5°-15° angle on the connector tip.
Angstrom
A unit of length in optical measurements where 1Ã = 10-10 meters, or 10-4 micrometers, or = 10-1 nanometers....
Angular Misalignment
The difference of a shaft's slope compared to the other shaft's slope. Sometimes referred to as gap or face.
Angular Misalignment Loss
Optical power loss caused by angular deviation from the optimum alignment of source to fiber, fiber to fiber, or...
Angular Tilt
The angle formed by the axes of two fibers to be joined.
Annealing
The process of heating a cooling a solid material, such as glass, to stabilize thermal or electrical properties and...
Annealing Furnace
An oven designed to anneal glass for the optical industry.
Anti Reflection Coatings
A layer applies to the back of laser output mirrors to reduce unwanted reflections that interrupt power.
Antiguide
A waveguide with a core that has a lower refractive index than the cladding. This object can remove unwanted...
Aperature
The area of a fiber core that will accept light, also known as light acceptance.
Apertometer
An instrument that measures the numerical aperture of a lens
Aramid Yarn
The part of optical fiber cable that provides support, protection and tensile strength. Commonly referred to as Kevlar, which...
Architecture
The way that hardware or software is structured. Network architecture defines the functions and description of data formats and...
Argon Ion Lasers
Powerful gas lasers that generate multiple watts of optical power in an output beam.
ARINC
Aeronautical Radio Incorporated
Armadillo Cable Assembly
A ruggedized duplex fiber optic cable assembly featuring a rigid plastic connector shell and integrated strain relief boot.
Armadillo Loopback
A ruggedized fiber optic test adapter designed to loop a signal from the Tx side of a port to...
Armor
A component on a communication cable that is intended to protect internal components, including buffer tubes and electrical conductors,...
Artificial Intelligence
The ability of a machine to perform certain functions normally associated with human intelligence, such as judgment, pattern recognition,...
Atomic Absorption Spectrophotometer
An instrument used to analyze the sharp resonance line of a sample that, in a flame, emits an atomic...
Attenuation
Power loss in an electrical or telecommunications system.
Attenuation Coefficient
The measure that determines how permeable a material is.
Attenuation Constant
The real part of the axial propagation constant for a particular mode.
Attenuation Limited Operation
The condition that occurs in a fiber optic link when the power of the received signal limits operation.
Attenuation Limited Power
The limitation on performance due to the amplitude of a received signal rather than a distortion.
Attenuation Meter
A device that measures power loss in fiber optic connectors, cables, or systems.
Attenuator
A device that induces loss in a fiber optic link, thus reducing signal power.
Automatic Optical Inspection
A system used to control or measure automatic industrial processes. It is composed of an optical module, a segmentation...
Average Power
The average amount of work done or energy transferred per unit time.
Average Wavelength
The mean of two wavelengths caused by the peak optical power dropping by half.
Axial Misalignment Loss
Optical power loss that is caused by two parallel fiber axes that are not on the same central axis.
Back Mounted Connector
Also referred to as rear mounted, a connector that mounts to the panel inside of a panel or box....
Back Reflection – Optical Return Loss
The loss that occurs (measured in - dB) when light changes direction in fiber and returns toward the source,...
Backbone
The main portion of a telecommunication network and the link between routers, switches, and bridges.
Backbone Cabling
Inter-building and intra-building cable connections located between entrance facilities, equipment rooms and telecom closets. This cabling consists of transmission...
Backbone System
A type of transmission network that carries high-speed telecom signals between regions. It can be used to describe the...
Backscattering
Light in fiber that has scattered toward the source. It is used to make OTDR measurements.
Balun
An adapter used to connect unbalanced coaxial transmission lines to a balanced two-wire system.
Band Marking
Also called ring marking, this is the practice of applying a colored mark to a conductor at regular intervals...
Band Spectral
An interval in the Electromagnetic Spectrum defined by two wavelengths, frequencies, or wave numbers. With Landsat, bands designate the...
Banding
An uncorrected radiometric artifact caused by forward and reverse scans that are radiometrically different.
Bandpass
Also referred to as passband, a range of frequencies that a bandpass filter permits to pass through.
Bandpass Filter
A filter that allows a certain range of frequencies through and prevents unwanted signals from getting through.
Bandwidth (BW)
The information carrying capacity of a system; the capacity of a telecom line to carry signals.
Bandwidth Distance Product
The value, equal to the product of the fiber's length and the 3-dB bandwidth of the optical signal, that...
Bandwidth Limited Operation
In fiber optics, the limitation on performance imposed by the system bandwidth rather than the amplitude of the signal.
Bandwidth Limited Pulses
Pulses with a duration as short as possible with their optical spectrum.
Banner Advertisement
A typically rectangular advertisement on a web site placed above, below, or on the sides of the sites main...
Barrier Layer
In the fabrication of an optical fiber, a layer that can be used to create a boundary against OH-ion...
Baseband
The simplest method of transmission on a local area network. The entire bandwidth of the cable is used to...
Baud
The number of signal level transitions per second in digital data. The term is often confused with bits per...
Baud Rate
The speed in which computers can transfer data through a modem using communications software.
Bayonet Coupling
A quick coupling mechanism for mating a plug onto a receptacle utilizing three equally spaced pins protruding from the...
Beam Attenuator
A device designed to decrease flux density or power per unit area of a light beam through absorption and...
Beam Bender
A mirror used to manipulate the beam in a laser system.
Beam Combining
A class of techniques for power scaling of laser sources by combining the outputs of multiple devices.
Beam Diameter
Also referred to as beam width, the length of any perpendicular line that intersects the beam axis. The...
Beam Divergence
The increase in beam diameter with increase of distance from the source.
Beam Expander
A system of optical components designed to increase the diameter of a radiation beam.
Beam Optics
A discipline within the broad study of optics that is specifically oriented toward the investigation of waves with small...
Beam Parameter Product
The product of beam radius and the beam divergence half-angle. The usual units are mm mrad (millimeters times milliradians). The...
Beam Pointing Fluctuations
Fluctuations of the propagation direction of a laser beam.
Beam Profilers
Devices for measuring the intensity profile of a laser beam.
Beam Quality
A measure for how well a laser beam can be focused.
Beam Radius
A measure of the transverse extension of a light beam.
Beam Waist
Location with minimum beam radius.
Beat
The signal formed when two signals, such as light waves, of different frequencies are present simultaneously in a nonlinear...
Beat Length
A characteristic of optical fiber used to calculate the fiber's ability to maintain polarization. The beat length describes the...
Beat Note
An oscillation of the optical intensity arising from the superposition of light with different optical frequencies.
Beauty Defect
A defect on or in an optical element that does not appreciably impair the function of the surface.
Bend Loss
1. A form of increased attenuation in a fiber that results from bending a fiber around a restrictive curvature (a...
Bend Radius
The radius of curvature that an optical fiber can bend without sustaining damage.
Bending of Light
The action occurring when light passes through an optical interface at other than normal incidence, i.e., refraction.
BER Floor
A limiting of the bit-error ratio (BER) in a digital fiber optic system as a function of received power...
Biconic
A connector type which has a taper sleeve which would be fixed to the fiber optic cable. When this...
Biconic Connector
A type of fiber optic connector consisting of two cone-shaped ferrules aligned by a mating sleeve.
Bidirectional
The ability for light to transmit in both directions through a fiber.
Bidirectional Reflectance
A unitless measure of the ratio of incoming to outgoing radiation created from converting a radiometrically calibrated image to...
Bifurcated Fiber
A branched fiber optic lightguide that performs both receiving and transmitting functions.
BIN Code
Basic identification number - color bands on the wire barrel end of a contact to identify contact part number....
Bit Error Rate (BER)
Bit Error Rate. The number of bit errors that occur within the space of one second. This measurement is...
Bit Period (T)
The amount of time required to transmit a logical one or a logical zero.
Bit Rate
(1) The number of bits of data transmitted over a phone line per second. You can usually figure how...
Block
A collection of transmitted information which is seen as a discrete entity. Usually has its own address, control, routing...
BNC
Popular coax bayonet style connector, often used for baseband video.
Boot
A form placed onto the boot adapter used to environmentally seal and/or strain-relieve a cable assembly.
Boot Adapter
A mechanical device with one side threaded onto the accessory thread of a connector (plug or receptacle) and the...
Bound Mode
In an optical fiber, a mode that (a) has a field intensity that decays monotonically in the transverse direction...
BPS
Bits per second. Term used by telecommunication engineers to describe bandwidth. Bytes per second is the term used by...
Bragg Grating
A filter that separates light into many colors via Bragg's law. Generally refers to a fiber Bragg grating used...
Bragg Scattering
Scattering of light caused by a change in refractive index, as used in Fiber Bragg Gratings and Distributed Bragg...
Braid
An essential part of many fiber-optic cable designs, consisting of a layer of woven yarn. Note: In the case...
Break Out Cable
Same as a Fan Out cable. This is a multiple fiber optic cables constructed in the tight buffered design....
Break Out Kit
Used to build up the outer diameter of fiber cable for connecting.
Breakdown Voltage
In avalanche photodiodes, the point at which an increase in the reverse bias voltage causes the current gain to...
Buffer
A protective coating applied directly on the fiber. Primary buffers encompass the 125 um cadding up to 250 um....
Buffer Coating
A protective layer, such as an acrylic polymer, applied over the fiber cladding for protective purposes.
Buffer Tube
A hard plastic tube, having an inside diameter several times that of a fiber, that holds one or more...
Buffered Fiber
Fiber optic cable protected with an additional material, usually hytrel or nylon, to provide ease in handling, connectorization and...
Buffering
It is used in two contexts: First, it refers to a protective material extruded directly on the fiber optic...
Bundle
(1) A group of optical fibers or electrical conductors, such as wires and coaxial cables, usually in a single...
Bundle of Fibers
A rigid or flexible group of fibers assembled in a unit. Coherent fiber bundles have fibers arranged in the...
Burn
A surface imperfection caused by a polisher running dry too long. It occurs with felt or plastic polishers, and...
Butt Splice
A joining of two fibers without optical connectors arranged end-to-end by means of a coupling. Fusion splicing is an...
C Band
A term coined by the IEEE to represent frequency range from 4 to 8 GHz that requires a large...
Cable
A single or multiple fibers enclosed within a protective covering.
Cable Assembly
A group of cables that has connectors located on one or both ends.
Cable Bend Radius
The measure of the smallest radius that a cable can bend without experiencing damage.
Cable Clamp
A mechanical device used to support a cable, provide strain relief and absorb vibration that may transmit from the...
Cable Signal Leakage
Excessive levels of radio frequency (RF) energy that leak from cable television systems can cause interference to communications users,...
Cables
One or more fibers surrounded by a protective casing.
Calibration
The adjustment of a measuring instrument or sensor that results in standardized measurements.
Calibration Data
Measurements related to the spectral or geometric characteristics of a sensor or radiation source. Calibration data is obtained through...
Calibration Parameter File
Computer files of fixed parameters used in the ground processing system to convert raw uncalibrated bits from a spacecraft...
Carrier Frequency
The carrier of a frequency wave selected to transmit information.
Catastrophic Failure
A failure in which device characteristics change quickly, typically in less than a second.
Center Wavelength – Laser
The nominal value of a central operating wavelength defined by a peak mode measurement where the effective optical power...
Center Wavelength – LED
The average of two wavelengths measured at the half amplitude points of the power spectrum lengths corresponding to the...
Centro Symmetrical Reflective Optics
An optical technique in which a concave mirror is used to control the coupling of light from one fiber...
Certificate of Compliance (C of C)
A certificate showing that the product being shipped meets customers' specifications.
Chalcogenide Glass
An infrared-transmitting material used in optical fibers for applications in the wavelength region from 2 to 11 µm.
Channel
A communication path or signal sent over an optical channel.
Channel Capacity
The maximum number of channels that a cable system can carry simultaneously.
Channel Coding
Data encoding and error correction techniques used to protect the integrity of data. Typically used in channels with high...
Channel Density
The number of channels per unit bandwidth that can be handled by a single optical fiber.
Channel Markers
A/B markers that easily identify the TX and RX Connector on each end of a fiber optic cable assembly....
Chromatic Bandwidth
The inverse of the Chromatic Dispersion.
Chromatic Dispersion
The temporary spreading of a pulse in an optical waveguide caused by the wavelength's dependence on the velocities of...
Cladding
In fiber optics, the material that surrounds the core of an optical fiber to contain core light while protecting...
Cladding Diameter
In the cross section of a realizable optical fiber, the average of the diameters of the smallest circle that...
Cladding Glass
Glass found around the core of a fiber that has a lower refractive index than the fiber.
Cladding Mode
In fiber optics, an undesired region that is confined to the cladding of an optical fiber due to the...
Cladding Mode Stripper
A device designed to remove modes that are propagating through the cladding by allowing them to radiate out of...
Cladding Ray
A ray that is reflected into the core of an optical fiber from the outer surface of the cladding.
Cleave
The process of scoring and breaking an optical fiber end so that it is perpendicular to the longitudinal axis...
Coated Optics
Optical elements with refracting or reflecting surfaces that have been coated with protective layers of dielectric/metallic material to reduce...
Coating
A material put on a fiber during the drawing process to protect it from the surrounding environment.
Coherence
A term describing light as waves that are in phase in both time and space.
Coherence Length
With respect to a laser, the greatest distance between two arms of an interferometric system that can obtain sufficient...
Coherence Time
The time over which the field correlation decays.
Coherent Bundle of Fibers
Fibers packaged together in a bundle in order to retain a fixed arrangement at the two ends and can...
Coherent Communications
In fiber optics, a communication system where the output of a local laser oscillator is mixed optically with a...
Coherent Light
This is light with parameters that are predictable and correlated at any point into time or space, particularly over...
Coherent Noise
Systematic periodic noise in image or calibration data, which can be characterized in terms of frequency, phase and amplitude....
Collimate
To align the axes of instruments so that they have the same spatial orientation along a common line.
Collimated Beams
Laser beams with a low beam divergence, which prevents the beam radius from experiencing significant changes within moderate propagation...
Collimation
The process of aligning an optical system's optical axes to an instrument's reference mechanical axes or surfaces.
Collimator
An optical instrument, consisting of a well-corrected objective lens with an illuminated slit or reticle at its focal plane,...
Combiner
A passive device that combines optical power from several input fibers at a common point.
Concentricity
The measurement in a cable or wire based on the location of the conductor's center, with respect to the...
Concentricity Error
In an optical fiber, the distance between the center of the two concentric circles that specify the cladding diameter...
Conduit
Pipe or tubing that houses and protects electrical cables.
Connecting Hardware
Hardware that terminates optical fiber cables with connectors and adapters. It provides a point for cross-­connecting between cabling segments...
Connector
A plug or a receptacle used to terminate or connect the electrical conductors of a cable and its individual...
Connector Body
The main portion of a connector to which other components are attached.
Connector Induced Fiber Loss
Part of the conductor insertion loss, expressed in dB, that results from impurities or structural changes to the fiber...
Connector Insertion Loss
Total optical power loss caused by insertion of an optical component such as a connector, splice or couple into...
Connector Loss
Energy loss encountered at connectors in optical fiber transmission systems, typically caused by mutual core displacement and fiber axis...
Connector Panel
The rear surface of a computer or peripheral device, which includes the connectors for peripheral devices or for the...
Connector Panel Module
A module designed for use with patch panels that contains 6, 8 or 12 connectorized fibers spliced to backbone...
Connector Plug
A device used to terminate an optical conductor cable.
Connector Receptacle
The fixed or stationary half of a connection that is mounted on a panel/bulkhead. Receptacles mate with plugs.
Connector Return Loss
The amount of power that is reflected from a connector to its interface, expressed as dB.
Connector Variation
Also known as optical connector variation, this is the maximum value in dB of the difference in insertion loss...
Constructive Interference
Any interference that increases the resultant signal's amplitude.
Contact
Pin or socket — the conductive element of a connector which actually makes contact for the purpose of conducting...
Contact Area
The actual area in contact (touching) between two conductors (pin and socket) permitting the flow of electrical current.
Contact Arrangement
The number of contacts, their size and spacing in a connector.
Contact Engagement Separation Force
The amount of force that is needed to engage or separate pin and socket contacts.
Contact Size
The number that indicates the size (or gauge) of the engaging end of the contact (e.g., size 20, size...
Convergence
Light rays bending toward each other, which allows communication system providers to deliver products and services that compete with...
Convergent Beam Sensing Mode
A type of photoelectric proximity mode sensing incorporating a lens system to focus the light from the emitter in...
Core
The center of an optical fiber that has a high refractive index and carries the light signal that has...
Core Area
The part of an optical fiber's cross-sectional area with a refractive index that is greater than that of the...
Core Diameter
The average of the diameters of the smallest circle of an optical fiber that can be circumscribed about the...
Core Eccentricity
A measure of the displacement of the center of the core in relation to the center of the cladding.
Core Ellipticity
A measure of the core's departure from roundness.
Core Less End Caps
End pieces attached to fibers that don't have a fiber core.
Coupled Modes
In fiber optics, a mode that shares energy among one or more other modes, all of which propagate together.
Coupler
Fiber optic component that distributes optical power among two or more ports; also used for coupling optical power between...
Coupling
The transfer of light going into and coming out of a fiber, not to be confused with a coupler...
Coupling Efficiency
The fraction of available output from one radiant source that is coupled and transmitted by an optical fiber.
Coupling Loss
The power loss suffered when light is coupled from one optical device to another. There can be intrinsic losses...
Coupling Nut Ring
The movable portion of a connector plug that aids in the coupling and uncoupling of a plug and a...
Coupling Ratio
The percentage of light that is transferred to a receiving output port in relation to the total power of...
Coupling Ratio Loss
The loss of optical power from one output port to the total output power, expressed as a percent.
Covered Groove
A technique used in integrated optics where a groove is cut on a substrate surface and covered by a...
Crimp
The physical compression (uniformed deformation) of a contact wire barrel around the conductor in order to captivate the conductor...
Crimp Contact
A contact, pin or socket whose wire barrel is a hollow cylinder into which a conductor is inserted. The...
Crimp Die
The portion of the crimp tool that shapes the crimp on the wire barrel.
Crimp Sleeve
A crimped metal cylinder that holds the connector to the cable through the cable's strength member.
Crimp Tool
A mechanical device that holds the crimp die and performs the crimping function.
Crimping
A pressure method that uses a tool to mechanically secure a contact (pin or socket) to a conductor (wire).
Critical Absorption Wavelength
The wavelength at which the absorption of a given element starts to demonstrate an inconstant value.
Critical Angle
The smallest angle of incidence at which total internal reflection occurs. The angle of incidence in a denser medium,...
Critical Phase Matching
A method used to obtain phase matching of a nonlinear process in a birefringent crystal.
Cross Calibration
The radiometrical comparison of sensors on two different satellites.
Cross Connect
Connections between terminal blocks on the two sides of a distribution frame or between terminals on a terminal block....
Cross Gain Modulation
Connections between two terminal blocks on the sides of a distribution frame or between terminals on a terminal block....
Cross Phase Modulation
A fiber nonlinearity caused by the nonlinear index of refraction of glass.
Cross Sections
Material parameters for quantifying the likelihood or rate of optical transition events.
Crosstalk
Interference between nearby conductors caused by stray energy that occurs when a receiver on one communication channel inadvertently receives...
Crush
A surface scratch or series of scratches formed by improper handling.
Crush Strength
An optical fiber's physical limit to withstand an applied force or weight that is perpendicular to the axis of...
Cutback
A method for measuring the attenuation or bandwidth of a fiber optic cable by first measuring the full length...
Cutback Measurements
A measurement of optical loss that is made by cutting a fiber to compare the loss of a short...
Cutback Method
A technique used to measure how much bare fiber is lost. Obtained by measuring the optical power transmitted through...
Cutback Technique
A technique for determining characteristics of optical fiber transmission. Characteristics are determined in four steps: performing the desired measurements...
Cutoff Mode
The highest order mode that will propagate in a waveguide at a certain frequency.
Cutoff Wavelength
The point in a wavelength beyond which single mode fiber only supports one mode of propagation.
Cuton Wavelength
The wavelength where the filter transmission increases beyond 5 percent.
Damped Least Squares
An organizational method in optical design computer systems that produces a number to measure the state of correction in...
Damping
Relative to time or distance, damping is the continuous conversion of energy into heat.
Dark Current
A current that flows in a photodetector when there is no radiation or optical power.
Dark Fiber
Installed without a transmitter or receiver, dark fiber is optical fiber that is unused in a cable. Sometimes, these...
Dark Mirror
Multilayer coating with both low radiant reflectance and radiant absorption, often used where control of stray light is critical.
Dark Noise
Noise produced in a photodetector when operating voltage is applied and a photocathode is shielded from external optical radiation.
Dark Operate Mode
An operating mode where a sensor is programmed to perform certain tasks. Tasks include generating output when light falls...
Data
Basic elements of information processed or produced by a computer. In fiber optics, data is transmitted by light.
Data Bus
A system in fiber optic data communication where several terminals are served by the same multiplexed signal.
Data Communications
The movement of encoded information through an electrical transmission system from one point to another.
Data Dependent Jitter
Jitter related to transmitted symbol sequence caused by limited bandwidth and imperfections in optical components. Also referred to as...
Data Dependent Jitter (DDJ)
A type of jitter that is related to the transmitted symbol sequence. DDJ is caused by the limited bandwidth...
Data Frame
Destination address, source address, length field, LLC data, pad and check frame sequence.
Data Link
A communication network between the nodes in a data transmission system.
Data Link Layer
Responsible for transmitting and receiving, passing data from the network to the physical layer.
Data Rate
Maximum number of bits of information per second in a data transmission system, expressed as bits per second (bps)....
dBC
Decibel relative to carrier level.
dBμ
Decibel referenced to microwatt.
dBm
Decibel below 1 milliwatt.
dBmV
Decibel millivolt. 0 dBmV = 1 millivolt across 75 ohms.
DBR
Distributed Bragg reflector (DBR) is a reflection of light caused by periodic changes in the refractive index in layers...
dBu
Decibels below 1.
DCE
(1) Data circuit-terminating equipment is the equipment that performs functions at the network end of a line between data...
Deblocking
Removal of optical elements from a block.
Decentration
The lack of coincidence between the optical and mechanical axes in a single element.
Decentration Aberration
An aberration that occurs in a lens system when one or more of the centers of the curvature of...
Decibel (DB)
A decibel (dB) is a unit of measurement for light transmission and can be used to express differences in...
Dedicated Line
A communications circuit or channel used exclusively by a particular subscriber, often when large amounts of data need to...
Deep
A concave surface with too much negative power.
Deeply Depressed Cladding Fiber
A single mode optical fiber with an outer cladding of the same refractive index as the core and an...
Deformable Mirror Device
A spatial light modulator with metallized polymer film over metal-oxide semiconductor field-effect transistors, leading to a laser readout beam's...
Degenerate Level
Two or more energy states are identical.
Degradation
A gradual decrease of output signal with constant light level input.
Delay Distortion
Distortion created from different signal frequencies with different propagation velocities through a medium.
Delay Line
A device to delay signal transmission for memory loops, sequential processing or built-in testing. This delay is achieved by...
Delay Time
An interval delay between the direction of a signal to the light-emitting diode and the attainment of 10% output...
Delta
The greatest relative difference in cladding and refractive index of core.
Demultiplex
The separation of channels multiplexed in order to share a common transmission medium. With fiber optic cables, it is...
Demultiplexer
A device separating a multiplexed signal into original components.
Demultiplexing
To separate two or more signals that were combined into one signal.
Demux
Abbreviation for demultiplexer.
Dense Wavelength-Division Multiplexing (DWDM)
To transmit signals of multiple wavelengths through the same fiber with close spacing. DWDM bands include: C-band, S-band and...
Density
Mass per unit volume.
Depolarization Loss
The loss of optical power in a laser resonator that is caused by the depolarization in a laser crystal.
Depolarizer
A device that reflects a polarized beam in all directions at right angles to its access with the goal...
Depth of Crimp
Distance the crimp die indenter penetrates the wire barrel.
Destination
Receiver of data.
Destination Address
A part of the message that indicates for whom it was intended.
Destructive Interference
Any interferences that decreases a signal.
Detector
A photodiode to convert optical signal to electrical signal.
Detector Noise Limited Operation
Operations in an optical communication system where the amplitude of pulses determines the distance between repeaters.
Detector Responsivity
Radiometric response of an electronic detector converting photons to voltage.
Detem
A device where the functions of an optical detector and emitter are combined.
Deterministic Jitter (DJ)
Timing distortions caused by normal circuit effects in the transmissions system.
Dextrogyrate
Rotation of the polarization plane of a light beam clockwise (or to the right).
Diameter Divergence Product
The diameter and the divergence angle of a laser beam.
Diameter Mismatch Loss
Loss of power at a joint occurring when the transmitting have has a greater diameter than the receiving half.
Dichroic Filter
Optical filter transmitting light selectively according to wavelength.
Dichroic Mirrors
Required for separating or combining laser beams with different wavelengths, these mirrors have a significantly different reflection or transmission...
Die Closure
When the crimp tool handle is fully closed, this is the distance between the crimp die indenters.
Dielectric
A material that is not metallic or conductive, like a glass fiber.
Dielectric Coatings
Thin film coating made of transparent dielectric materials for laser mirrors or anti-reflection coating to modify the reflective properties...
Dielectric Filter
An optical fiber selectively transmitting one wavelength and reflecting others, depending on interference effects inside a structure. Also referred...
Dielectric Mirrors
Mirrors with multiple thin layers of transparent optical materials.
Dielectric Strength
Voltage that an insulation can withstand before breaking down.