Fiber Optic Terms In CONEC Corporation

Glossary Fiber Optic Technical Terms	German

Absorption	Weakening (loss) of radiation when it passes through a material (part of the radiant energy of light, for example, is converted into heat).
Armoring	Protective element (usually steel wire or tape) used on cables with special operational requirements e.g. direct burial, undersea, in mines and for rodent protection.
Attenuation	The factor by which the signal power at the end of the cable has decreased relative to the power at the start of the cable. Main causes in optical fibers: scattering, absorption, light losses in connectors and splices.
Backscattering technique	Technique for measuring the attenuation along an optical fiber.
Bandwidth	Frequency at which the magnitude of the transfer function of an optical fiber has fallen to half of the value that it had at ‘zero’ frequency; i.e. the attenuation of the light signal has risen by 3 dB.
Central member	A member running through the center of a cable; in fiber-optic cables usually a strength member.
Cladding	The dielectric material surrounding the core of an optical fiber and having a lower refractive index than the core.
Coating	Composite layer applied to the surface of the fiber cladding to provide mechanical protection.
Connector	Easily demountable plug-in connection between two optical fibers. As a rule the insertion loss (see insertion loss) of a plug-in connection is higher than that of a splice (see splice).
Core glass	Core of a glass fiber. It has a higher refractive index than the cladding glass.
Coupler	Passive component for the transmission of light between light source and fiber or between several fibers.
Crimping	Compressing a sleeve around the fiber/buffer in order to produce reliable mechanical protection.
Dispersion	Dispersion causes light pulses in a fiber to spread in time. A distinction is made between multimode distortion, material dispersion and fiber dispersion.
Doping	Controlled addition of small quantities of an impurity to a pure substance in order to change its characteristics, e.g. increase the refractive index (see refractive index) of the fiber core. Electromagnetic compatibility EMC Electromagnetic interference immunity and interference emission of a cable/system.
FDDI	Fiber-optic network with dual, counter-rotating ring topology and (Fiber Distributed Data Interface) 100 Mbit/s bandwidth.
Fiber multiplexing	Transmission method in which each transmission channel is assigned a fiber.
Fiber ribbon	Fibers arranged parallel to each other and equally spaced, bonded in a flat configuration by a coating. Several fiber ribbons can be placed on each other to form a stack.
FITL (Fiber in the Loop)	Fiber in the local line network. A distinction is made according to where the fiber terminates, as follows: • FTTB – fiber to the building • FTTC – fiber to the curb • FTTH – fiber to the home, and • FTTP – fiber to the pedestal.
Frequency	Number of complete cycles per second (in Hz).
FRNC	Flame Retardant Non Corrosive LS0H Material.
FTTD (Fiber to the Desk)	Cabling in which optical fibers extend to the desk.
Graded index profile	Refractive index profile of an optical fiber. The refractive index of the fiber core decreases continuously – usually parabolically – toward the cladding.
GRP element (GRP = glass fiber reinforced composite).	Antibuckling and strength member made of glass filaments
Indoor cables	Cables for applications inside buildings. They are generally unsuitable for outdoor use.
Insertion loss	Attenuation caused by the insertion of an optical component into an optical transmission path.
ISDN (Integrated Services Digital Network)	Data, voice and images are switched and transmitted through the digital network via one port.
LAN (Local Area Network)	Local network for serial transmissions between independent terminal equipments.
Layer cable	Cable in which the fiber buffer tubes (transmission elements) are arranged in layers around a central member (see central member).
Length of lay	The pitch of the stranding of multifiber buffer tubes.
LID (Local Injection and Detection)	The “local light injection and detection system” is used for the fast, trouble-free alignment of the fibers. It consists of two bent-fiber couplers (source and detector); light is injected into the fiber on the source side and the optical power transmitted is measured on the detector side. Optimum fiber alignment is achieved when maximum optical power is detected.
L-PAS (Lens Profile Alignment System)	Video image analyzer; this system is used for positioning the fibers in x. y and z axes. The fiber ends to be fused are imaged on the sensor of a CCD camera. The electrooptically converted signal is used for displaying the fibers, for checking the fiber positions on the monitor and for image analysis.
Loose buffer tube	Several fibers in a common loose buffer tube.
Microbending	Minute curvature in a fiber causing light loss and hence increased attenuation.
Modes	All the light waves that can propagate in an optical fiber.
Multimode fiber	Optical fiber whose core diameter is large relative to the wavelength (see wavelength) of the light, thus allowing a large number of modes (see modes) to propagate.
Optical fiber	Transparent dielectric waveguide for transmitting signals using electromagnetic waves in the optical frequency range.
Optical waveguide	optical fiber (see optical fiber)
Outdoor cables	Cables designed to satisfy all the requirements for outdoor installation (e.g. buried or in ducts, in the air or under water).
OVD Method (outside vapor deposition method)	Method of producing optical fibers by deposition from the gas phase onto the outer surface of a rotating substrate rod.
Pigtail	Short length of optical fiber with a connector at one end.
PON (passive optical network)	Network for FITL (see FITL) with passive components, such as couplers, splitters and connectors.
Reflection	Return of waves due to a mismatch.
Refraction	Change in the direction of propagation of a ray (wave) at the interface between two media with different refractive index (see refractive index).
Refractive index	Factor by which the velocity of light in an optical medium (e.g. glass) is lower than it is in a vacuum.
Ribbon cable	Cable with fiber ribbons (see fiber ribbons).
Single-mode fiber	Optical fiber whose core diameter is so small relative to the wavelength (see wavelength) of the light that only one mode (see mode) can propagate.
Slotted core cable	Cable with fibers or fiber ribbons located in grooves in the surface of the central member.
Splice	Permanent connection between two optical fibers that is made by fusion or bonding.
Splitter	Optical component for dividing the optical power from one fiber among several other fibers.
Star coupler	Active or passive component which provides an even distribution of optical power in an identical number of incoming and outgoing fibers.
Step index profile	Fiber with an abrupt decrease in refractive index at the interface between core and cladding. The refractive indexes for core and cladding are constant.
Strength member	Structural element in the cable for absorbing tensile and compressive forces.
Tight-buffered fiber	Fiber with a closely fitting buffer tube.
Time-division multiplexing	Transmission method by means of which several digital signals arriving in parallel are transmitted in a serial data stream over a single fiber.
Wavelength	Length of the full cycles (period) of a wave. The three wavelength ranges normally used in optical communications are 850 nm, 1300 nm and 1550 nm.
Wavelength-division multiplexing	Transmission method by means of which several signals are transmitted simultaneously at different wavelengths over a single fiber.