Fiber Optic Glossary : C

• C Band
  A range of wavelengths from 1530 to 1565 nm. In this region, erbium-doped amplifiers (EDFAs) have highest gain. See EDFA...
• Cable
  One or more fibers enclosed in protective coverings and strength members.
• Cable Assembly
  An optical fiber cable that has connectors installed on one or both ends.
• Cable Bend Radius
  Cable bend radius during installation infers that the cable is experiencing a tensile load. Free bend infers a lower allowable bend...
• Cable clamp
  A mechanical device attached to the accessory threads at the rear of a plug or receptacle to support the cable...
• Cable Jacket
  The outermost protective covering applied over the internal cable elements (i.e., core, cladding, buffer, and strength member).
• Cable Plant
  The cable plant consists of all the optical elements. For example, fiber, connectors, splices, etc. between a transmitter and a...
• Cable Television
  Communications system that distributes broadcast and non-broadcast signals as well as a multiplicity of satellite signals, original programming and other...
• Caching
  An access-driven form of replication. Data is replicated and stored locally as it is referenced; only an initial reference to...
• Campus Bridge
  Brings a new dimension to internetworking, the ability to link LAN segments to 30 kilometers or more via single mode fiber...
• Carbon Dioxide Laser
  A gas laser in which the energy-state transitions between vibrational and rotational states of CO2 molecules give emission at long...
• Carrier Envelope Offset
  The offset between the optical phase and the maximum of the wave envelope of an optical pulse.
• Carrier Frequency
  The electromagnetic wave frequency selected to transmit information. Optical carrier frequency is from the infrared, visible or ultraviolet spectrum areas (1012...
• Carrier Injection
  The process whereby light is emitted at the junction of N- and P-type semiconductors when an external electric source is...
• Carrier Sense Multiple Access With Collision Detection
  1. A technique used to control the transmission channel of a local area network to ensure that there is no conflict...
• Carrier Signal
  A continuous waveform (usually electrical) whose properties are capable of being modualted or impressed with a second information carrying signal. The...
• Carrier to Noise Ratio
  The ratio, in decibels, of the level of the carrier to that of the noise in a receiver's IF bandwidth...
• Carrier to Noise Ratio (CNR)
  The ratio, in decibels, of the level of the carrier to that of the noise in a receiver's IF bandwidth...
• Cascade Amplification
  In a series of amplifiers, amplification by each of the preceding output.
• Cascade Tube
  An instrument consisting of a high-voltage vacuum tube used to form hard x-rays or high-speed ion beams. By partitioning the...
• Catastrophic Failure
  A failure in which the device characteristics change suddenly, generally in less than a second.
• Catastrophic Optical Damage
  Catastrophic optical damage occurs when the semiconductor in the emission region is melted and recrystallized.
• Category 5e
  Category 5 (CAT5) cable is a popular twisted pair copper cable. It is used for Ethernet cable applications. Category 5e...
• Cathode
  A negatively charged electrical element providing electrons for an electrical discharge.
• CATV
  An abbreviation for Community Antenna Television or cable TV.
• Causality
  The concept of relating effects to causes, or the compatibility of phenomena with this concept.
• Cavity
  In a laser, the optical resonator formed by two coaxial mirrors, one totally and one partially reflective, positioned so that...
• Cavity Dumping
  A Q-switch method that can result in extreme pulse shortening.
• CCIR
  Abbreviation for Consultative Committee on Radio.
• CCITT
  Abbreviation for Comite Consulatif International de Telegraphic et Telephonic. An international communications standards. Based in Geneva, Switzerland. Concerned with devising and...
• CCTV
  Abbreviation for closed-circuit television.An arrangement in which programs are directly transmitted to specific users and not broadcast to the...
• CD
  Abbreviation for compact disk. Often used to describe high-quality audio, CD-quality audio, or short-wavelength lasers; CD laser.
• CDMA
  Abbreviation for code-division multiple access. A coding scheme in which multiple channels are independently coded for transmission over a single...
• Cell
  A fixed-length data packet transmitted in certain digital systems such as ATM.
• Center Wavelength (Laser)
  1. The nominal value central operating wavelength defined by a peak mode measurement where the effective optical power resides. 2. The...
• Center Wavelength (LED)
  1. The average of the two wavelengths measured at the half amplitude points of the power spectrum. 2. The wavelength of...
• Central Member
  The center component of a cable. It serves as an antibuckling element to resist temperature-induced stresses. Sometimes serves as a strength...
• Central Office
  1. The place where communications common carriers terminate customer lines and locate switching equipment that interconnects those lines. 2. The places...
• Central Office (CO)
  A common carrier switching office in which users' lines terminate. The nerve center of a communications system.
• Centro Symmetrical Reflective Optics
  An optical technique in which a concave mirror is used to control coupling of light from one fiber optic cable...
• Ceramic Gain Media
  Laser gain media which have a ceramic microscopic structure.
• CGA
  Abbreviation for color graphics adapter. A low-resolution color standard for computer monitors.
• Chalcogenide Glass
  An infrared-transmitting material used in optical fibers for applications in the wavelength region from 2 to 11 µm.
• Channel
  1. A communications path or the signal sent over a channel. Through multiplexing several channels, voice channels can be transmitted over...
• Channel Capacity
  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 bit...
• Channel Density
  The number of channels per unit bandwidth handled by a single optical fiber.
• Channel Electron Multiplier
  A photoelectric detector consisting of a glass tube internally coated with a low conductance material. Voltage applied along the tube...
• Channel Impedance
  The parallel resistance and capacitance appearing between the active guard ring junctions in a silicon photodiode.
• 
  Channel Markers
  A/B markers easily identify the TX and RX connector on each end of a fiber optic cable assembly. These channel...
• Channel Spacing
  The amount of bandwidth allocated per channel.
• Channel Substrate Planar Growth
  The creation of a diode laser structure by liquid-phase epitaxy over a grooved substrate.
• Characteristic Angle
  The angle at which a given mode propagates down an optical fiber.
• Chelate Laser
  A laser having a rare-earth chelate within a plastic host as the lasing material. The chelate laser is easily pumped...
• Chemical Laser
  A laser that relies on chemical activity instead of electrical energy to produce the pumping action necessary to form pulses...
• Chemiluminescence
  Luminescence arising from chemical reactions.
• Chirp
  In laser diodes, the shift of the laser's center wavelength during single pulse durations due to laser instability.
• Chirped Pulse
  A pulse in which the wavelength changes during the duration of the pulse.
• Chirped Pulse Amplification Laser
  A laser whose pulses are expanded, using gratings and optical fibers, before amplification and compressed to increase beam intensity without...
• Chromatic Bandwidth
  The inverse of the Chromatic Dispersion.
• Chromatic Dispersion
  The temporal spreading of a pulse in an optical waveguide caused by the wavelength dependence of the velocities of...
• Chromium Doped Gain Media
  Laser gain media doped with chromium ions.
• Circuit
  Originally a physical connection that transmits electricity or signals. Now also a communication channel that guarantees a fixed transmission...
• Circuit Switching
  Making temporary physical or virtual connections between two points, which guarantees a fixed transmission capacity.
• Circular Birefringence
  The optical phenomenon in which right circularly polarized light transmitted by an active medium travels at a different velocity than...
• Circular Dichroism
  The optical phenomenon in which planar polarization is converted to elliptical polarization when plane-polarized light traverses an active medium.
• Circulator
  Passive three-port devices that couple light from Port 1 to 2 and Port 2 to 3 and have high isolation...
• 
  Cladding
  The low-refractive-index material that surrounds the core of an optical fiber to contain core light while protecting against surface contaminant...
• Cladding Diameter
  In the cross section of a realizable optical fiber, ideally circular, but in practice assumed to a first approximation to...
• Cladding Glass
  The glass that is found around the glass core of a fiber, and that has a lower refractive index that...
• Cladding Mode
  An undesired mode that is confined to the cladding of an optical fiber by virtue of the fact that the...
• Cladding Mode Stripper
  A mechanism or device, especially a coating with a refractive index equal to or slightly greater that that of an...
• Cladding Ray
  A ray that is reflected into the core of an optical fiber from the outer surface of the cladding.
• Classification Duration
  For a laser, the maximum exposure time that the laser design allows.
• 
  Cleave
  The process of scoring and breaking the optical fiber end in order to terminate a connector. Also known as...
• Cleaving
  The process of separating an optical fiber by a controlled fracture of the glass, for the purpose of obtaining a fiber...
• CLEO
  An acronym for Conference on Lasers and Electro-Optics.
• Clock
  1. An electronic component that emits consistent signals, like a metronome, that paces a computer's operations. 2. An oscillator-generated signal that...
• Clustering
  The tendency of laser-active ions in laser gain media to form clusters in their host medium.
• Cm
  Abbreviation for centimeter. Approximately 0.4 inches.
• CMOS
  Abbreviation for complementary metal oxide semiconductor. A family of IC's.Particularly useful for low-speed or low-power applications.
• CMTS
  Abbreviation for cable modem termination system.
• CNR
  Abbreviation for Carrier-to-Noise Ratio. The ratio, in decibels, of the level of the carrier to that of the noise in...
• Coadding
  A method of improving the signal-to-noise ratio of an interferogram by adding another interferogram to it.
• Coarse Wavelength division Multiplexing (CWDM)
  CWDM allows eight or fewer channels to be stacked in the 1550 nm region of optical fiber, the C-Band.
• Coated Optics
  Optical elements having refracting or reflecting surfaces that have been coated with one or more layers of dielectric or metallic...
• Coating
  A material put on a fiber during the drawing process to protect it from the environment.
• Coax
  An abbreviation for coaxial cable.
• Coaxial contact
  A contact with two conductive surfaces – a center contact and a surrounding coaxial sleeve.
• Code
  A specific way of using symbols and rules to represent information.
• Coder
  Digital information transformed into pulses of electricity, digitized as ones and zeros with no errors.
• Coherence
  A term describing light as waves which are in phase in both time and space. Monochromaticity and low divergence are two...
• Coherence Length
  That length over which energy in two separate waves remains constant. With respect to a laser, the greatest distance between...
• Coherence Time
  A measure of temporal coherence, expressed as the time over which the field correlation decays.
• Coherent Bundle
  See aligned bundle.
• Coherent Bundle of Fibers
  Fibers packaged together in a bundle so they retain a fixed arrangement at the two ends and can transmit an...
• Coherent Communications
  In fiber optics, a communication system where the output of a local laser oscillator is mixed optically with a received...
• Coherent Light
  This is light of which all parameters are predictable and correlated at any point into time or space, particularly over an...
• Coherent Radiation
  Radiation composed of wave trains vibrating in phase with each other. Simply expressed: parallel rays of light.
• Coherent States
  A special kind of pure quantum-mechanical states.

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