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E D F A. Seminar By: Geno G James. EE-566 Optical Communication. What is EDFA. Type of Optical amplifier Stands for “Erbium Doped Fiber Amplifier” Used to boost the intensity of optical signals being carried through a fiber optic communications system
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EDFA Seminar By: Geno G James EE-566 Optical Communication
What is EDFA • Type of Optical amplifier • Stands for “Erbium Doped Fiber Amplifier” • Used to boost the intensity of optical signals being carried through a fiber optic communications system • Has a fiber whose core is heavily doped with Erbium ions • Works on the concept of stimulated emission • Operates in the C band (1530-1560) and L band (1570-1610)
Origin of EDFA (Who, When and Where) • Prof.David Payne and team • Published the research paper in the year 1987 • At the University of Southampton, UK
Why Erbium? • Erbium has several important properties that make it an excellent choice for an optical amplifier • Erbium ions (Er3+) have quantum levels that allows them to be stimulated to emit in the 1540nm band, which is the band that has the least power loss in most silica-based fiber. • Erbium's quantum levels also allow it to be excited by a signal at either 980nm or 1480nm, both of which silica-based fiber can carry without great losses
How it works • Energy band of Erbium Demo
Block diagram of EDFA • Copropogating Pump EDFA
Block diagram of EDFA • Counterpropogating Pump EDFA
Characteristics of EDFA • Gain and Noise
Advantages • Commercially available in C-band & L-band • Insensitivity to light polarization state • High gain • Low noise figure: 4.5 dB to 6dB • No distortion at high bit rates • Simultaneous amplification of wavelength division multiplexed signals • Immunity to cross talk among wavelength multiplexed channels
Advantages (Cont…) • Do not require high speed electronics • Independent of bit rate (Bit rate transparency)
Drawbacks • Pump laser necessary • Need to use a gain equalizer for multistage amplification • Difficult to integrate with other components • Dropping channels can give rise to errors in surviving channels
Companies • You name them………. and they are there
References • DWDM Fundamentals, Components and Applications by Jean-Pierre Laude • Fiber Optic Communication Technology by Djafar K.Mynbaev and Lowell L.Scheiner • www.soton.ac.uk • www.photon-x.net/tech/edfa.htm • www.webopedia.com • www.mse.vt.edu