The rapid growth of the internet and data traffic in optical fiber communication networks has stimulated the study of wideband optical. Length of raman amplifier in edfa we fixed the length of the fiber and found the values of the. Typically, the optical pump is introduced at the end of a length of fiber in order to provide optical gain that increases towards the end of the fiber. Optical amplifiers amplify an optical signal directly, without the. The difference between edfa and raman amplifier the main di erence. The advancement in laser technology led to the interest of fra. Performance evaluation of edfa, raman and soa optical. The main advantage that this amplifier has over the edfa is that it generates verylessnoise. Thorlabs optical amplifiers are available as complete benchtop systems or as pigtailed butterfly packages. Another type of distributed amplifier is the raman amplifier, where no rare earth dopant is required, and stimulated raman scattering is used for amplification. Beyond a certain distance the number of photons in pulses becomes too small to be detected. The overall hybrid soaedfaraman amplifier noise figure versus dwdm channels frequency is plotted for the raman amplifier pumping conditions that produces best gain and gain flatness performance. Compared to a edfa, the main advantages of raman ampli cation are an improved noise gure and improved gain atness.
Edfa vs raman optical amplifier fiber cabling solutions. The aim of this article is to establish a comparison between the edfa erbium doped fibre amplifier and soa semiconductor optical amplifier optical amplifiers in the wdm wavelength division. Optical amplifier edfa erbiumdoped fiber amplifier for. Thorlabs also offers a benchtop erbiumdoped fiber link amplifier. Lumentum offers the most comprehensive portfolio of highperformance amplifiers raman, high power edfas, wide dynamic gain range edfas, edfa arrays in the industry. Finisars hybrid ramanedfa module enables costeffective deployment of ultralong haul networks as well as the extension of existing longhaul, regional and metro networks, without the need for 3r oeo regeneration. Raman amplifier with flatgain bandwidth of 100 nm the 1480nm wdm pumping unit developed in order to increase edfa output can be readily adapted for broadband raman amplifiers. Performance characteristics of dualpumped hybrid edfa. Optical amplifiers thorlabs optical amplifiers are available as complete benchtop systems or as pigtailed butterfly packages. Raman amplifier is another important optical amplifier other than edfa. Applications for distributed raman amplification optical.
As mentioned earlier, the shape of the raman gain spectrum depends. In a raman amplifier, the signal is amplified due to stimulated raman. The overall hybrid soa edfa raman amplifier noise figure versus dwdm channels frequency is plotted for the raman amplifier pumping conditions that produces best gain and gain flatness performance. Dec 16, 2014 edfa, semiconductor optical amplifier soa and fiber raman amplifier. Edfa, semiconductor optical amplifier soa and fiber raman amplifier.
Optical amplifiers amplify an optical signal directly, without the need to first convert it to. Performance evaluation of edfa, raman and soa optical amplifier for wdm systems. White paper introduction to edfa technology june 2009 1 introduction shortly after their commercialization in the early 1990s, erbium doped fiber amplifiers edfas became a key enabling technology for optical communication networks, and have since comprised the vast majority of all optical amplifiers deployed in the field. Edfa stands for erbium doped fiber amplifier and it is one type of many different optical amplifiers. Soaedfaraman optical amplifier for dwdm systems at the edge. The variation in output power for raman, edfa and soa are 3. Optical amplifiers are important in optical communication and laser physics. This chapter describes the technologies needed for cascading an erbiumdoped fiber amplifier edfa and a fiber raman amplifier fra or ra to create a hybrid amplifier ha, the edfaraman ha. While the raman amplification occurs in the transmission fiber itself so unlike edfas it is a distributed amplification. Soaedfaraman optical amplifier for dwdm systems at the. Two bands have developed in the third transmission window the conventional, or cband, from approximately 1525 nm 1565 nm, and the long, or lband, from. Rp photonics encyclopedia distributed amplifiers, erbium.
They enable the characterization of the gain, noise figure, and output power under unsaturated and saturated signal input regime. Intrinsic method based of changing spectroscopic properties of edfa where as extrinsic method are used on. An ultrahigh gain and efficient amplifier based on raman. To equalize gain spectrum of edfa either intrinsic or extrinsic methods may be used. Gain and noise figure analysis of erbium doped fiber.
This paper is divided into different sections for transmission of 32. Introduction to optical amplifiers 417 a raman amplifier is distributed over a long span of optical fiber. Our line of benchtop optical amplifiers includes ytterbiumdoped fiber amplifiers ydfas, a praseodymiumdoped fluoride fiber amplifier pdfa, and erbiumdoped fiber amplifiers edfas. Before the comparison of the different types of optical amplifiers, lets take a closer look at fiber optic amplifier. In raman amplification, around the 1500nm band, gain is produced at approximately 110 nm on the longwavelength side, so that if the pumping. The raman amplifier has greater gain ranges while edfa amplifier costs less. The most practical optical amplifiers to date include the soa and edfa types. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. In order to construct a raman amplifier using optical f i b e ra sg a i nm e d i u m,p u m pa n ds i g n a ll i g h tw a v e sh a v et o be jo in tly l aun ch ed in to th e sa me f ibe r fo r sti.
Typically the raman noise figure is 2 to 0 db, which is about 6 db better than the edfa noise figure. Abstract in this paper 10 gbps wdm systems at 16, 32 and 64 channels have been investigated with edfa, raman and soa amplifiers individually and the performance has been compared on the basis of transmission distance and dispersion with and without nonlinearities. If you continue browsing the site, you agree to the use of cookies on this website. Raman amplifier noise factor is defined as the osnr at the input of the amplifier to the osnr at the output of the amplifier. Mar 03, 2011 edfa stands for erbium doped fiber amplifier and it is one type of many different optical amplifiers. Gain and noise figure analysis of erbium doped fiber amplifier by four stage enhancement and analysis. What is the difference between edfa and raman amplifiers in. Its typical application is in edfa spans where additional gain is required but the osnr limit. It typically provides an improvement in performance that cannot be obtained by edfa alone. Edfa vs raman amplifier as far as i know, edfa and raman amplifiers are the two main optical options for signal amplification in longerhaul fiber links. The raman amplifier is typically much more costly and has less gain than anerbium doped fiber amplifier edfa amplifier. Erbium doped fiber amplifier edfa is an optical amplifier that uses a doped optical fiber as a gain medium to amplify an optical signal. Raman gain can occur at any signal wavelength by proper choice of the pump wavelength. Thorlabs corepumped erbiumdoped fiber amplifiers edfas offer 20 dbm 100 mw output power with a low noise figure of edfa with minimal sensitivi.
Initially, researchers showed great interest in edfa. Finisars hybrid raman edfa module enables costeffective deployment of ultralong haul networks as well as the extension of existing longhaul, regional and metro networks, without the need for 3r oeo regeneration. After knowing the basic information of edfa and raman optical amplifiers, you must consider that the raman amplifier performs better for two main reasons. Edfa uses the principle of stimulated radiation of edf fiber to amplify the optical. Today, we are going to study and compare different types of optical amplifiers in this paper. Edfa, or erbiumdoped fiber amplifier, is the most deployed optical amplifier in the wdm system that uses the erbiumdoped fiber as optical amplification medium to directly enhance the signals. Currently it is not possible to create a fully optical communication system without a software tool which simulates an optical communication line in real conditions prior to its construction. The ratio between the power of amplified spontaneous emission and the power of incoherent optical noise is quantitatively determined by detailed analysis of experimental data in the pump powers range.
The raman amplifier is typically much more costly and has less gain than an erbium doped fiber amplifier edfa amplifier. The splitter will have a finite loss and this adds directly to the noise figure of the amplifier. Pdf the difference between edfa and raman amplifier. Fiber raman and brillouin amplifiers rare earth doped fiber amplifiers erbium edfa 1500 nm, praseodymium pdfa 0 nm the most practical optical amplifiers to date include the soa and edfa types. The raman optical amplifier is based on an entirely different principle than edfas or conventional lasers. Both the gain and noise figure are experimentally studied and. For fibers with low drs noise, the raman noise figure due to ase is much better than the edfa noise figure. Erbiumdoped fiber amplifier edfa and raman amplifier ra are the. In edfas and conventional lasers, atoms are pumped to a high. However, the bandwidth shortfall can be made up elsewhere. The optical pulses in fibers are energized by utilizing optical fiber amplifiers. Chandigarh group of colleges, ladran, mohali, india. Gain spectrum, gain saturation, and amplifier noise.
In edfa, a relatively highpowered beam of light is mixed with the input signal using a wavelength selective coupler. An optical signal can be amplified in the optical domain without. The erbiumdoped fiber amplifier edfa is the most deployed fiber amplifier as its amplification window coincides with the third transmission window of silicabased optical fiber. The hybrid module consists of a count\ erpropagating raman pump unit and a variable gain \vg\ edfa. This hybrid edfara optical amplifier hoa is dual pumped. Jan 04, 2012 raman amplifier is another important optical amplifier other than edfa. Abstract in this paper, the hybrid optical amplifier composed. This paper suggests a hybrid amplifier using an erbiumdoped fiber amplifier edfa and raman amplifier ra with dualpump configuration. Home forums fiber edfaraman hybrid amplifier gain edfaraman hybrid amplifier gain dennis jacq joined may 2016 participant hi guys, i am currently simulating edfaraman amplifier in terms of output gain base on the journal gain flattening of edfa using hybrid edfaraman amplifier with reduced channel spacing. An optical signal can be amplified in the optical domain without being converted to electronic domain and back. This chapter describes the technologies needed for cascading an erbiumdoped fiber amplifier edfa and a fiber raman amplifier fra or ra to create a. In case of nonequalized edfa, system results in signal distortion and poor signaltonoise ratio performance. The formation dynamics of the optical noise in a silica single mode fiber smf as function of the pump power variation in the counter pumped fiber raman amplifier fra is experimentally studied. Firstly, it has a wide band, while the band of edfa is only from 1525 nm to 1565 nm and 1570 nm to 1610 nm.
Wdm optical network analysis using edfa and raman amplifier. Pdf comparative study of performance of edfaraman hybrid. Mar 05, 2018 it makes raman easier to understand, lists down i ts benefits, requirements and applications. However, additional issues arise in raman ampli cation that are not present in edfa. Gain flattening of edfa using hybrid edfaraman amplifier w. The edfa is forward biased with 980 nm while the ra is reverse biased with 1450 nm in the dualpump configuration. As light pulses propagate along the optical fiber, their energy dissipates. Edfa uses the principle of stimulated radiation of edf b er to. The optimum length of edfa is 7m and use forward pumping configuration for reduce effect o f noise. In edfas and conventional lasers, atoms are pumped to a high energy state and then drop to a lower state, releasing their energy, when a suitable wavelength photon passes nearby. This chapter describes the technologies needed for cascading an erbiumdoped fiber amplifier edfa and a fiber raman amplifier fra or ra to create a hybrid amplifier ha, the edfa raman ha.
Raman scattering or stokes scattering and contributes to noise in the fiber. Pdf in this paper, comparative study of the gain and noise figure for edfa raman hybrid amplifier, edfa and raman amplifier was done. Therefore it is used only for speciality applications. Raman amplifier worldwide leading supplier in fiber optic network, fttx, fiber cabling, fiber testing and integrated network solutions. What is the difference between edfa and raman amplifiers. Erbium doped fiber amplifier edfa is an optical amplifier. New pumping methods and materials are also improving the performance of raman amplifiers. In the case of edfa, the amplification occurs in the erbium doped fiber located within the closed amplification module so edfa are classified as lumped amplifiers. Raman amplification arising from the excitation of a density echelon in plasma could lead to amplifiers that significantly exceed current power limits of conventional laser media.
Gain flattening of edfa using hybrid edfa raman amplifier w ith reduced channel spacing. The amplifying medium is a glass optical fiber doped with erbium ions. Design and development of erbium doped fiber amplifiers. Erbium doped fibre amplifier edfa and fiber raman amplifier fra are such two technologies that do not need conversion rather they amplify and transmit the optical signal. Kalera, 20, 1 performance evaluation of edfa, raman and soa optical amplifier for wdm systems compared on the basis of transmission distance 40200 km and dispersion 210 psnmkm with and without nonlinearities.
Comparison of the optical amplifiers edfa and soa based on. Raman amplifier implementation in the optical network. Again, the transmission fiber can hardly be optimized for raman amplification, as the propagation losses need to be low, and the pump light is also subject to propagation losses. At least the loss limitation can be partially canceled out by the introduction of optical. In this way, a raman amplifier can be combinedfa booster or inlineed with a n.
Types of optical amplifiers, raman amplifier vs edfa. An erbium doped fiber amplifier is a suitable component for optical fiber networks serving as a wide range of. Apr 08, 2017 with edfa being the default amplifier for use in dwdm transmission, raman amplifier is found critical and effective in complementing the edfa for transmission distance expansion. The ramanactive medium is often an optical fiber, although it can also be a bulk crystal, a waveguide in a photonic integrated circuit. As a market and technology leader in optical amplifiers for over two decades, lumentum leverages vertical integration and deep knowhow to continue to offer points of. Before the comparison of the different types of optical amplifiers, lets take a. The application of raman amplifier in dwdm network is demonstrated below. The better output power is provided by the edfa amplifier 12.
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