Transcript Slide 1
EDFA Seminar By: EE-566 Geno G James 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 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….) 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 JeanPierre 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 Thank You