Edfa, transient characteristics, optical fiber communication abstract. Flat, parabolic, and cubic gain models are based on the following equations for the material gain and gain peak wavelength. Edfas consist of optical couplers to combine pump and signal. Edfa stands for erbiumdoped fiber amplifiers, which is an optical amplifier that uses a doped optical fiber as a gain medium to amplify an optical signal.
Study of single and multi wavelengthwdm edfa gain control. Erbium doped fiber amplifier is the major type of the fiber amplifier used to boost the signal in the wdm fiber optic system, as we know it is wdm that increase the capacity of the fiber. Pdf a new erbiumdoped fibre amplifier edfa is demonstrated using a. What is the tradeoff between one type and the other. Gain and noise figure analysis of erbium doped fiber. An optical amplifier amplifies an optical signal directly, without the need to first convert it to an electrical signal. Gain spectrum, gain saturation, and amplifier noise.
Erbium doped fiber amplifiers is a bonafide work done by mr. White paper introduction to edfa technology optical. Frequency response amplifiers do not have the same gain at all frequencies. 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. Moreover, uniform illumination of the cores simplifies modal gain. Erbium doped fiber amplifier edfa is an important element in wdm networks but the gain of signals fluctuates due to channel adddrop networks. Hybrid amplifier properties by using a single raman pump, the onoff gain is necessarily sloped. Thin film filters long period fiber gratings chirped fiber bragg gratings 24. Edfas consist of optical couplers to combine pump and signal lights injected to active fiber, unidirectional. Are there areas where raman amplifiers are clearly better. A preamplifier operates at the receiving end of an optical link. Opti 500 c, spring 2011, lecture 23, introduction to optical amplifiers 5 typical edfa. A metastable energy level at 4i2, with a long decay time 10 ms, is essential for collecting ions for a population inversion.
An edfa is typically operated in one of two operating modes. An erbium doped fiber amplifier is a suitable component for optical fiber networks serving as a wide range of. The db onoff gain increases in an approximately linear fashion with wavelength until it reaches a peak at 1600nm. Wavelength division multiplexing is a technology for combine number of. Multicom carries a full line of low noise high power 1550nm optical amplifiers. Optical input optical output pump current pump current. Gain and noise figure performance of erbium doped fiber amplifiers edfa a. The gain flatness of erbiumdoped fiber amplifier edfa is a key device for wavelength division. The primary difference is that they do not have a resonator. Erbiumdoped fiber amplifiers are designed to amplify optical signals to increase the optical transmission distance over fiber. Edfa, wdm system, gain flatness, constant gain, multi.
The emcore mafa 5000 series micro erbium doped fiber amplifier. Gain flattening of edfa using hybrid edfaraman amplifier. The edfa amplification region varies from application to application and can be. Edfa gain block module is an ideal building block for oem systems integration where there is a requirement to amplify a 1550 nm signal for a broad range of applications including catv systems, rfmicrowave fiber optic links, sensing and control systems, and more. Raman amplifier gain equations gr is called the raman gain coefficient. Optical amplifiers, edfa, erbium doped fiber, gain, noise figure. The term doping refers to the process of using chemical elements to facilitate results. Cem cokrak, ahmet altuncu 1114 here, nt ionm 3 is called total ionic population and is equal to the total of populations in two energy.
Comparison of the optical amplifiers edfa and soa based on. Hybrid amplifiers are best alternative for broadening and flattening of the gain. After knowing the basic information of edfa and raman optical amplifiers, you must consider that the raman amplifier performs better for two main reasons. Gain and noise figure analysis of erbium doped fiber amplifier by four stage enhancement and analysis. Erbium doped fiber amplifier edfa used in wdm system. I have copropagating pump laser and tunable optical signal and i want to measure the gain of edfa amplifier from the optical spectrum analyser osa. These instruments can be customized to accommodate a wide range of input signal levels. It is the range of optical wavelengths for which the amplifier yields a usable gain. Kindly direct me how to calculate the gain of the edfa. Gain flattening of edfa using hybrid edfaraman amplifier w.
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. Gain analysis of edf amplifier based wdm system using. At least the loss limitation can be partially canceled out by the introduction of optical ampli. The gain for an erbiumdoped fiber amplifier is shown in figure 7. In addition, remote control of the pump current is supported by sending serial commands via a usb 2. A characteristic plot of gain and noise figure for an erbium doped fiber amplifier pumped 30 mw at 980 nm. Gain and noise figure performance of erbiumdoped fiber amplifiers. Erbium doped fiber amplifiers edfas are key devices in. 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.
This was until polarization dependent gain was observed in longhaul optical amplified systems as well as in a single erbium doped fiber amplifier. Also, the spectral shape of the gain and not only its magnitude is substantially influenced by the average degree of excitation of the erbium ions, because these have a quasithreelevel transition. The signal to be amplified and a pump laser are multiplexed into a doped fiber and the signal is amplified. The gain, ase power and noise figure variations of a fo rward pumped edfa as functions. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Pdf enhancement in the gain of edfa in fibre optic. The optimum length of edfa is 7m and use forward pumping configuration for reduce effect o f noise. Pdf gain and noise figure performance of erbium doped. The curves show that an edfa amplifies light over a bandwidth of approximately 30 to 40 nm. Finisars single channel micro edfa is a costeffective micro processorcontrolled module for amplifying single channels in the cband. The amplifier consists of an erbium doped fiber amplifier and a discrete raman amplifier, which has isolated raman fibers pumped simultaneously at two, three wavelengths.
Fiber driver optical amplifier modules provide multifunction, low noise, erbiumdoped fiber amplifier edfa solutions that are ideal for metro dense wavelength division multiplexing dwdm applications. Machine learning assisted edfa gain ripple modelling. It acts basically as a sort of a lasing chamber without the. Why in saturated gain region gain is lower than in unsaturated small signal gain region. In steady state, dn2 dt 0, the ratio of level 1 and level 2 population to the total population can be written as. Although the effect is extremely small for a single amplifier, it accumulates in every amplifier stage and. Soa model provides many options for modelling of semiconductor amplifier. A gainflattened version and a preamplifier version for a lower input power 30 dbm, are also available. It is uses this doped optical fiber as a gain medium to amplify an optical signal. Pdf flatgain wideband erbium doped fiber amplifier by. Theoretical analysis on the transient characteristics of. Amplification of the multiwavelength signal by using edfa. The development of erbiumdoped fiber amplifiers edfa in the latter half of the 1990s supported amplification of signals using wavelengthdivision multiplexing wdm and permitted the spread of longdistance, large capacity communications, such as optical submarine cables and optical subscriber systems.
Edfa amplifier archives tutorials of fiber optic products. Edfa gain equalization gain equalization can be accomplished in several ways. Since its invention, the edfa has been deemed as a polarizationinsensitive device. Design and analysis of all optical switch architecture. The raman amplifier has greater gain ranges while edfa amplifier costs less. Design and development of erbium doped fiber amplifiers. In the shown case, the active fiber is pumped with light from two laser diodes bidirectional pumping, although unidirectional pumping in the forward or backward direction codirectional and counterdirectional pumping. Pdf the gain flatness of erbiumdoped fiber amplifier edfa is a key. Optical ampsraman and erbiumdoped fiber amplifiers pp. Is it just a matter of edfas being cheaper and raman amplifiers having greater gain ranges, or is there something more major that i am missing.
This type of fiber is called erbiumdoped fiber, and is the key component in amplifying an optical signal in an edfa. Is it just a matter of edfa s being cheaper and raman amplifiers having greater gain ranges, or is there something more major that i am missing. These edfa s feature high output power as well as high gain values with very low noise. But these solution are not feasible in case of multiwavelength system.
They enable the characterization of the gain, noise figure, and output power under unsaturated and saturated signal input regime. Pdf a model for the prediction of edfa gain in a space. The shape of the erbium gain spectrum depends on the absorption and emission cross sections, which depend on the host glass. Lumentums automatic gain control with fast transient suppression on edfas is a notable example of a performance attribute that has been hailed by nems and network operators as setting the industry benchmark for robustness, resilience, and survivability within the most demanding deployment scenarios. I have measured first the signal power without using the edfa and then, the peak power and the average noise power after using the edfa. The pump current of the erbiumdoped fiber amplifier is adjustable through the instruments front panel, allowing the user to vary the gain and output power of the amplifier. Wavelength dependent edfa gain ripple has an impact on connections osnr performance. Rp photonics encyclopedia erbiumdoped fiber amplifiers.
For the uninitiated, edfa erbium doped fiber amplifier. Flat gain wideband erbium doped fiber amplifier by combining two different doped. The optical input power controls the edfa saturation state and. The gain of an amplifier is governed, not only by the components transistors etc. Edfa stands for erbium doped fiber amplifier and it is one type of many different optical amplifiers. The ap3370 edfa module could be combined with ap3314 power meter modules in the platform. Packetlights plil dwdm platform is a 1u chassis designed to support a variety of optical applications such as extending the optical link power budget for building long distance dwdm solutions. Multichannel gain and noise figure evaluation of ramanedfa. The amplifier is provided in a micro 45x70x12 mm package, and exhibits low power consumption allowing it to be easily i ntegrated onto space and power constrained transponder line cards.
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. Jan 27, 2009 can you provide a pointer to information about the edfa you are using, and be more specific about the power levels you want to run at. This positive slope is complemented by the edfa design which has. The erbium erdoped fibre amplifier edfa with a flattened gain at cband 15301565 nm is a key device for wavelength division multiplexing wdm systems in modern optical networks1,2. At least the loss limitation can be partially canceled out by the introduction of optical. Optical ampsraman and erbium doped fiber amplifiers edfas pp.
Analysis of gain and nf using raman and hybrid rfaedfa. As for sdm optical amplifiers, corepumped multimode and multicore edfas have previ. Stimulated emission in the amplifiers gain medium causes amplification of. Edfa gain optimization for wdm system universiti teknologi. Hybrid edfa amplifier, the system analyzed by using one stage 5mraman amplifier. Opti 500 c, spring 2011, lecture 23, introduction to optical amplifiers 4 fiber raman amplifier. In this paper the results of simulation of erbiumdoped fiber amplifier edfa characteristics are presented. These lband edfa s are designed with high power and high reliability pump lasers and pump combiners to provide excellent long term reliability. An erbium doped fiber amplifier edfa consists of a piece of fiber of length l, whose core is uniformly doped with erbium ions. Performance analysis of edfa for different pumping.
In erbium doped fiber amplifier, for the most part two pump wavelengths. Common fiber optical amplifiers include erbiumdoped fiber amplifier or edfa optical amplifier, raman fiber amplifier, and silicon optical amplifier soa. The structure of a typical edfa is shown in figure 1. Enhancement in the gain of edfa in fibre optic communication.
Gain master software used to simulate the edfa with different length, input power and pump powers. Edfa has large gain bandwidth, which is typically tens of nanometers and thus actually it is enough to amplify data channels with the highest data rates. Erbium doped fiber amplifier edfa is a optical amplifier that uses a fiber which has been lightly doped with rare earth ion i. The most common example is the erbium doped fiber amplifier edfa, where the core of a silica fiber is doped with trivalent erbium ions and can be efficiently pumped with a laser at or near a wavelength of 980 nm or 1480 nm, and exhibits gain in the 1550 nm region. A black box model bbm of common environment is introduced to characterize the gain of erbiumdoped fiber amplifier edfa for any wavelength in the range of 15401560 nm in the radiation. Thorlabs corepumped erbiumdoped fiber amplifiers edfas offer 20 dbm 100 mw output power with a low noise figure of edfa is a device that amplifies an optical fiber signal. It features medium to low input power, medium output. E rbiumdoped f iber a mplifier an edfa is an optical repeater device that is used to boost the level of optical signals being carried through a fiber optic rfog or overlay system. The em316ea family of cband edfa optical amplifiers is part of the fiber driver optical multiservice platform solution. Experimental study of edfa gainblock for booster amplifier. Such ions can be thought of as simple twolevel systems, i. It is used in the telecommunications field and in various types of research fields. Fundamental design of a distributed erbiumdoped fiber amplifier for.
A typical setup of a simple erbiumdoped fiber amplifier edfa is shown in figure 1. Pdf edfa gain optimization for wdm system researchgate. In the agc mode the amplifier gain is kept constant, whereas in apc mode the amplifier output power is kept constant. 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. Erbium laser amplifier has become one of the important components indispensable in optical fiber communication for its high gain, high pumping efficiency, polarizationindependent and small crosstalk between signals, etc. Edfa gain and signal output power are usually measured as a function of wavelength and input signal. Along with a portable design, ap3370 edfa modules provide stable saturated output power up to 22 dbm and noise. Its core is the erbiumdoped optical fiber, which is typically a singlemode fiber. Mar 03, 2011 edfa stands for erbium doped fiber amplifier and it is one type of many different optical amplifiers. Keywords erbium doped fiber amplifier, erbium doped fiber laser, lasing, amplification 1. Consequently, the tunable laser is the most important test equipment in optical amplifier edfa testing, in particular because these amplifiers are the key elements in wdm systems. At this part, we analyze the gain and nf by using the two stages hybrid amplifier with edfa and raman amplifiers 1 raman edfa at first, the system is analyzed by using edfa raman with first stage 10km length of raman have.