As we know when signal travels along a wire or in the air from source to the destination, the signal is changed or distorted by the path conditions. Rp photonics encyclopedia fiber amplifiers, edfa, ydfa. Edfa optical amplifier user manual 2 general information 2. Boosting of an optical signal without any conversion of. Introduction of optical amplifier tutorials of fiber. 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.
During operation as an optical amplifier, light is coupled into the waveguide at z 0. Opti 500 c, spring 2011, lecture 23, introduction to optical amplifiers 5 typical edfa characteristics. An inline amplifier is used to restore the optical signal to its original power level. Introdution to optical amplifiers fiber optical networking. Without the need to first convert it to an electrical signal, the optical amplifiers are now used instead of repeaters. A semiconductor optical amplifier is an optical amplifier based on a semiconductor gain medium. 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. Finally, when light comes out at z l, its power is much higher compared to what it was at z 0. A booster optical amplifier boa is a polarization sensitive device that only amplifies light with a specific polarization. An optical amplifier may be considered as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Thorlabs optical amplifiers are available as complete benchtop systems or as pigtailed butterfly packages. This page compares optical repeater vs optical amplifier and mentions functional difference between optical repeater and optical amplifier. An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. A large signal input power is considered in this case, since high signal input helps to produce high output power, which is necessary to boosterpower amplifiers.
Optical amplifiers vs regenerators 1 of 2 transparent. 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. Edfa education kit manual page 2 of 26 generated by stimulated emission. Optically isolated amplifiers are available at mouser electronics. This selection guide seeks to help endusers to identify the amplifiers that. Amplifiers introduction amplifiers are used extensively in electronic circuits to make an electronic signal bigger without affecting it in any other way. Optical amplifier modules product data sheet ciena. The optical signal is injected into this fiber, along with the light from a special pump laser that is designed to excite the erbium ions. Design and development of erbium doped fiber amplifiers. An optical preamplifier is used at the end of the optical fiber link in order to increase the sensitivity of an optical receiver.
As we know, there are several types of optical amplifiers. As these amplifiers are used for optical fiber communication projects so we shall go through their main characteristics which are amplifier gain and span length, wavelength bandwidth and noise. 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 analyze the noise behavior of a complete transmission line, as shown in fig. Gain saturation is exhibited in the curves shown in figure 9. Optical amplifier how is optical amplifier abbreviated. The soa fundamental lower limit for the noise figure is not substantially different from any phase insensitive linear amplifier e. Our boas are pigtailed with pm fiber and will amplify light aligned to the slow axis of the input fiber connector. What the heck is optical class a 2channel home audio. Regenerators specific to bit rate and modulation format used. Semiconductor optical amplifiers soas as preamplifiers. Generally we think of amplifiers as audio amplifiers in the radios, cd players and stereos we use around the home. Semiconductor optical amplifier outputlevel control that accepts a wide range of input power and delivers constant output power is essential for inline optical amplifiers, optical burst and packet systems and in all optical regeneration and reshaping 2r. Abstract all optical systems exploiting dense wavelength division multiplexing systems dwdms have emerged through implementation of optical amplifiers.
With an edfa and raman the minimum optical power level occurs toward the middle, not the end, of the fiber. A booster amplifier is used to increase the optical output of an optical transmitter just before the signal enters an optical fiber to compensate for attenuation of the signal as it travels in the optical fiber. Optical amplifiers are important in optical communication and laser physics. A variable gain optical amplifier, in which homogeneous gain broadening is dominant, has first and second fixed gain rareearth doped optical waveguide amplifiers 21, 23 optically in series together with an intervening variable attenuation optical attenuator 22. Optical amplifier, as the name implies, is a device that amplifies an input optical signal.
Potential use for optical switching opti 500 c, spring 2011, lecture 23, introduction to optical amplifiers 1. Optical amplifiers free download as powerpoint presentation. Optical fiber transmission has revolutionized networking and communication systems. As the light propagates inside the waveguide it gets amplified. Raman amplifiers used in conjunction with edfas semiconductor optical amplifiers small package potential use for lowcost applications potential use for optical switching opti 500 c, spring 2011, lecture 23, introduction to optical amplifiers 1 types of optical amplifiers. It can amplify all wdm channels together, and is generally.
Optical amplifier is an important technology for optical communication networks. Ciena has expanded the optical layer functionality of the 4200 by introducing two optical amplifier oa modules, which extend transport up to km without regeneration. Optical amplifiers article about optical amplifiers by. At least the loss limitation can be partially canceled out by the introduction of optical. Introduction to optical amplifiers 917 cannot exceed the pump power. Types of optical amplifiers, raman amplifier vs edfa. Our line of benchtop optical amplifiers includes ytterbiumdoped fiber amplifiers ydfas, a praseodymiumdoped fluoride fiber amplifier pdfa, and erbiumdoped fiber amplifiers edfas. Model fa3524s, with dual 21 dbm outputs, requires a special back plate, bpf3, that is also provided with this module. A narrow band optical filter is used to reduce transmission of amplified spontaneous emission frequency components. It is essentially like a laser diode where the end mirrors have been replaced with antireflection coatings. Thorlabs also offers a benchtop erbiumdoped fiber link amplifier developed by our strategic partner.
As the power in the input signal is increased, there must be a power at which the amplifier gain decreases. Amplifier with optical input recommendations please avforums. A system with optical amplifiers can be more easily upgraded to higher bit rate without replacing the amplifiers optical amplifiers have large gain bandwidths key enabler of dwdm. This post is going to help you get a better understanding of optical amplifier. Introduction to optical amplifiers 417 a raman amplifier is distributed over a long span of optical fiber. To transmit a signals over long distances 100km, to compensate attenuation losses. Together with wavelengthdivision multiplexing wdm technology, which allows the transmission of multiple channels over. White paper introduction to optical amplifiers june 2010 1 introduction optical amplifiers are a key enabling technology for optical communication networks. The resultant optical gain depends both on the optical frequency and the local beam intensity within the amplifier section. Optical amplifiers venkat venkataramanan instute for opcal.
Due to the small transition cross sections, the saturation energy is fairly high, e. In terms of gain saturation, fiber amplifiers are very different from semiconductor optical amplifiers soas. By providing optical gain to seven cwdm channels spectrally located between 1490 and 1610 nm, the amplifier can extend the reach of a cwdm optical bus well beyond the 100km limit. There are two principal types of optical amplifier. They have a similar structure to fabryperot laser diodes but with antireflection design elements at the end faces. Notice the very hard saturation of the gcsoa in the figure on the right. An inline amplifier is used to restore regenerate the optical signal to its original power level. Introduction to optical amplifiers 4 fiber raman amplifier. Optical amplifier archives fiber optic cabling solutions.
An optical fiber amplifier is a fiber optic device used to amplify optical signals directly without conversion into electrical signals. The amplification factor or gain can be higher than 1,000 30 db in some devices. Finisar optical amplifiers selection guide finisar offers a wide selection of optical amplifiers, ranging in optical and electrical specification parameters, and in a variety of form factors and communications interfaces. I suspect this amplifier design is doing something similar, except in this case, its using the optical couplersensor to adjust the bias current based on the level of output of the output transistors, instead of merely limiting amplifier output. Many of the advances in optical networks have been made possible by the advent of the optical amplifier. At the heart of edfa technology is the erbium doped fiber edf, which is a conventional silica fiber doped with erbium. Our benchtop boas are available with center wavelengths at 1050, 0, 1550, 1590, and 1625 nm.
A metastable energy level at 4i2, with a long decay time 10 ms, is essential for collecting ions for a population inversion. Semiconductor optical amplifiers booster optical amplifiers are amplifiers which use a semiconductor to provide the gain medium. Unlike regenerators, which have to convert light to electricity in order to amplify it and then convert it back again to light, the optical amplifier amplifies the light signal itself. The optical signal is attenuated as it travels in the optical fiber. In contrast, an ideal optical amplifier is designed to directly amplifier any input optical signal, without needing to transform it first to an electronic signal. For a general introduction to optical amplifiers, please see finisars white paper introducti on to optical amplifiers. An optical amplifier may be thought of as a laser without. Difference between optical repeater vs optical amplifier.
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