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 Has a fiber whose core is heavily doped with Erbium ions Works on the concept of stimulated emission Operates in the C band ( ) and L band ( )

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

Basic block diagram of EDFA

Block diagram of EDFA Copropogating Pump EDFA

Block diagram of EDFA Counterpropogating Pump EDFA

Characteristics of EDFA Gain and Noise

Characteristics of EDFA (Contd….)

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

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