Fiber Optic :: Glossary :: E

EDFA - Erbium-doped fiber amplifier.

EIA - Electronics Industries Association. A standards association that publishes test procedures.

8B/10B encoding - A signal modulation scheme in which either 4 bits are encoded into a 5-bit word or eight bits are encoded into a 10-bit word. This scheme ensures that too many consecutive zeros do not occur. It is used in ESCON and Fiber Channel.

802.3 network - A 10 MBPS CSMA/CD bus based LAN; commonly called Ethernet.

802.5 network - A token passing ring network operating at 4 or 16 MBPS.

EMC - Electromagnetic compatibility

EMD - Equilibrium mode distribution.

EMI - Electromagnetic interference. It is any electrical or electromagnetic interference that causes an undesirable response, degradation or failure in electronic equipment. Fiber optic cables neither emits nor receives EMI.

Emitter - Term used for a light source.

Encoding - A scheme to represent digital ones and zeros through combining high and low voltage states.

End separation - The distance between the ends of 2 joined fiber optic cables. End separation causes an extrinsic loss that depends on the joining hardware and method.

End to End Loss - The optical loss on an installed fiber optic cable data link path. This loss consists of the loss due to the fiber optic cable, splices and connectors.

Equilibrium mode distribution - The steady modal state of a multi-mode fiber optic cable in which the relative power distribution among the modes is independent of the fiber optic cable length.

Erbium-doped fiber amplifier - A type of fiber optic cable that amplifies 1550 nm optical signals when pumped with a 980-1480 nm light source.

ESCON - An IBM channel control system based on fiber optic.

ESKA - Trade mark of plastic fiber optic cable manufactured by Mitsubishi Rayon Corp.

ESKA GIGA - Graded index plastic fiber optic cable manufactured by Mitsubishi Rayon Corp.

ESKA MEGA - Trade mark of plastic fiber optic cable manufactured by Mitsubishi Rayon Corp.

Excess loss - There are 2 contexts in which it is used. First, in a fiber optic coupler it is the optical loss from that portion of light that does not emerge from the nominally operational ports of the device. Secondly, it is the ratio of the total output power of a passive component to the input power.

Extrinsic Losses - Signal loss in transmission down fiber optic cable caused by imperfect alignment of fiber optic cables joined by a connector or splice. Contributors to this loss include angular misalignment, axial misalignment, end separation and end finish - any imperfect joining caused by connector or splice.