FO600 Datasheet, PDF (48/57 Pages) Extech Instruments Corporation. – FiberMeter Optical Power Meter

UNIT 5
Appendices
Glossary
Absorption. The loss of power in an optical fiber, resulting from conversion of optical power into heat and
caused principally by impurities, such as transition metals and hydroxyl ions, and also by exposure to nuclear
radiation.
Acceptance Angle. The half-angle of the cone within which incident light is totally internally reflected by the
fiber core. It is equal to arcsin (NA).
Application Cabling Standard. A cabling standard that has been developed for a specific network protocol,
such as Ethernet. These standards use pre-defined link budgets for optical loss measurements.
Attenuation. A general term indicating a decrease in power from one point to another. In optical fibers, it is
measured in decibels per kilometer at a specified wavelength.
Bandwidth. The transmission capacity of a system.
Buffering. 1. A protective material extruded directly on the fiber coating to protect the fiber from the
environment (tight buffering). 2. Extruding a tube around the coated fiber to allow isolation of the fiber from
stresses on the cable (loose buffered)
Buffer Tubes. Loose-fitting covering over optical fibers used for protection and isolation.
Bundle. Many individual fibers contained within a single jacket or buffer tube. Also, a group of buffered fibers
distinguished in some fashion from another group in the same cable core.
Cladding. The outer concentric layer that surrounds the fiber core and has a lower index of refraction.
Connector. A mechanical device used to provide a means for aligning, attaching, and achieving continuity
between fibers.
Consolidation Point. A location for interconnection between horizontal cables that extend from building
pathways and horizontal cables that extend into work area pathways.
Core. The central, light-carrying part of an optical fiber; it has an index of refraction higher than that of the
surrounding cladding.
Cross-Connection. A connection scheme between cabling runs, subsystems, and equipment using patch
cords or jumpers that attach to connecting hardware on each end.
Decibel (dB). In fiber optics, a standard logarithmic unit for the ratio of the power that was received over the
power that was originally sent.
dBm. Decibel referenced to a milliwatt.
dBµ. Decibel referenced to a microwatt.
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