This constitutes a substantial improvement in gain flatness compared to the existing wideband optical fiber amplifiers. Unfortunately, flat spectral gain for the full range of controlled gain values is. Wide spectral band amplification with relative flat gain 20 db useful for. The second value is for units with the osc z determines if the unit supports integrated optical supervisory channel for endtoend communications. In this way, a raman amplifier can be combinedfa booster or inlineed with a n. An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. Optics hybrid flat gain c band optical amplifier with zr based erbium doped fiber and semiconductor optical amplifier1 n. Intrinsic gain is not flat over the c and l band must be engineered to flatten the effective gain system application sometimes require equalizer. The amplifier consists of two stages where zredf and edf operating in the. An efficient gainflattened cband optical amplifier is demonstrated using a hybrid configuration with a zirconiabased erbiumdoped fibre zredf and a semiconductor optical amplifier soa. The proposed pa achieves a power added efficiency of 40%56% for the entire band. Ii presents the simulated design of hybrid amplifier optical circuit and agc for each. An efficient gainflattened lband optical amplifier is demonstrated using a hybrid configuration with a distributed raman amplifier dra and an erbiumdoped fiber amplifier edfa for 160.
Broadband and gainflattened optical fiber amplifiers. Recently, a novel optimization procedure has been developed that allows for a choice of pump frequencies and powers in order to achieve the best possible gain flatness over a specified signal bandwidth 2, 3. Thorlabs optical amplifiers are available as complete benchtop systems or as pigtailed butterfly packages. Gain flattened cband hybrid optical amplifier achieving high. Doublepumped fiber optical parametric amplifier with flat gain over 47nm bandwidth using a conventional dispersionshifted fiber. The amplification window of an optical amplifier is the range of optical wavelengths for which the amplifier yields a usable gain. During operation as an optical amplifier, light is coupled into the waveguide at z 0.
However, the gain spectrum of an optical amplifier, which, for wavelength division multiplexed wdm systems and networks, typically operates in deep saturation, depends strongly on the input power to an optical amplifier. The amplification window is determined by the spectroscopic properties of the dopant ions, the glass structure of the optical fiber, and the wavelength and power of the pump laser. 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. Intrinsic gain is not flat over the c and l band must be engineered to flatten the effective gain system application sometimes. Pdf hybrid flat gain cband optical amplifier with zrbased erbium. Optical amplifiers for intermediate line amplifier ila.
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. Pdf doublepumped fiber optical parametric amplifier. This amplifier design will be helpful for catv applications and telecommunication networks. The wavelengthdependent gain for both lp01 and lp11 modes is about 0. The proposed eydfa fopa hybrid amplifier is investigated over a wavelength range of 15331565 nm for 160. An efficient optical link which provides flat gain over cband has been designed using a raman fibre amplifier and an erbium doped fibre amplifier edfa in a hybrid configuration for dense wave. Pdf flat gain on cband using ramanedfa hybrid optical. Optical amplifiers venkat venkataramanan instute for opcal. Hybrid distributed ramanedfa amplifier with hybrid automatic gain. One of the most promising gain equalizing techniques is the longperiod fiber grating. Introduction because the gain bandwidth of erbiumdoped fiber amplifiers edfa is much narrower than the low loss window of standard optical communication fibers, there is growing interest in wideband flat gain optical fiber amplifiers. Pdf flatgain wideband erbium doped fiber amplifier by. But this is not enough to accurately calculate ase noise spectral density, because the spontaneous emission factor n sp is a function of both wavelength and the carrier inversion level. The solid lines illustrate the response of two individual amplifier.
Optical amplifiers for intermediate line amplifier ila elimination the first db value for maximum span optical budget represents budget for units without the osc. Our line of benchtop optical amplifiers includes ytterbiumdoped fiber amplifiers ydfas, a praseodymiumdoped fluoride fiber amplifier pdfa, and erbiumdoped fiber amplifiers edfas. Wideband flat gain optical amplifier using hafnia and. An optical amplifier may be considered as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Gain flattened cband hybrid optical amplifier achieving. Dec 16, 2014 however, unlike a repeater, an optical amplifier amplify optical signal directly without electric and electric optical transformation. Aug 27, 2002 an optical fiber amplifier comprising. Figure 6 exemplifies the optical gain spectrum of a hybrid optical amplifier.
The amplifier utilizes a twostage structure with a midway isolator to improve flat gain characteristic and reduce noise figure. The amplification factor for every signal channel can be expressed in terms of the power integrals, as. For an optical amplifier, the measurement of optical gain spectrum g. An efficient gain flattened cband optical amplifier is demonstrated using a hybrid configuration with a zirconiabased erbiumdoped fibre zredf and a semiconductor optical amplifier soa. At least the loss limitation can be partially canceled out by the introduction of optical.
Many configurations are used to flatten the edfa gain. The amplifier utilizes a twostage structure with a. Performance analysis of flat gain wideband raman amplifier. Request pdf wideband flat gain optical amplifier using hafnia and zirconia erbium codoped fibres in doublepass parallel configuration a new compact and wideband erbiumdoped fibre. Gain bandwidth gain saturation noise properties of ideal optical amplifiers provide high gain 30 db or more have a wide spectral bandwidth to allow several wavelengths to be transmitted provide uniform i. May 04, 1999 for these reasons an amplifier has to maintain a flat gain spectra for a large dynamic range of input signals. The parameters are optimized to achieve a flat gain of 28. White paper introduction to optical amplifiers finisar corporation.
The most prevalent optical amplifier is erbium doped fiber amplifiers edfa that has a wavelength dependent nonflat gain spectrum. The obtained high and flat gain, along with the low noise figure, justifies the feasibility of the proposed amplifier for applications in broadband longhaul dwdm systems. Quantitatively, gain is a measure of the ability of a laser medium to increase optical power. Wdm amplifiers providing both flat gain and a large operating gain range require a more complex design see finisars white paper introduction to edfa. As the light propagates inside the waveguide it gets amplified.
Typical raman gain spectrum g of a silica fiber at pump wavelength 1 m. It is based on the optimum parameter configuration of a singlybased raman amplifier and edfa. Optical amplifier with wide flat gain dynamic range corning. Pdf hybrid flat gain cband optical amplifier with zrbased. Pdf an efficient optical link which provides flat gain over cband has been designed using a raman fibre amplifier and an erbium doped fibre. The resultant optical gain depends both on the optical frequency and the local beam intensity within the amplifier section. Pdf doublepumped fiber optical parametric amplifier with. In this paper, a hybrid wideband optical amplifier with a flat gain characteristic is proposed using a combination of zredf and edf as the gain medium. A stateoftheart gain bandwidth of 75 nm 15301605 nm is achieved. High power transfer efficiency from pump to signal power 50%. We show that by solving the inverse amplifier design problem, relative gain flatness well below 1% can be achieved over bandwidths of up to 12 thz without any gain equalization devices.
In order to maintain the gain flatness even under variable operational conditions, control schemes of the optical fiber amplifiers are also a critical issue. Inset shows the linear attenuation spectrum a silica fiber in the low loss window 14001700 nm. Optimal design of flatgain wideband fiber raman amplifiers. Normally employing a hybrid optical amplifier, consisting of two separate optical amplifiers, allows for separate amplification, one for the lower 40 nm band and the second for the upper 40 nm band. The peak gain wavelengths and gain bandwidths of soa and edfa depend on the band structures of semiconductor and rare earth materials used, while a raman amplifier has the peak gain at an optical frequency approximately thz lower than that of the optical pump when silica optical fiber is used. The best parameter for both amplification has been analyze in terms of its input signal. Pdf hybrid flat gain cband optical amplifier with zr. A modern wideband and flat gain erbiumdoped fiber amplifier edfa is suggested and accomplished, by employing a recently fabricated. Broadband flat gain optical amplifier lucent technologies inc. Wideband and flat gain series erbium doped fiber amplifier using. To ensure flat gain response, a novel idea of integrating a microstrip high pass filter hpf in the input matching network is proposed.
Pdf a new erbiumdoped fibre amplifier edfa is demonstrated using a combination of newly developed erbium zirconia codoped fiber zredf and the. Thorlabs praseodymiumdoped fiber amplifier pdfa offers high gain 20 db small signal gain, high output power 16 dbm, and a low noise figure optical networks as either a booster amplifier or preamplifier. Edfa is proposed to obtain a better performance in term of gain, noise figure and flat gain. Further, a comparison with eydfasingle pump fopa configuration shows that much better gain flatness is obtained for the proposed hybrid amplifier. Introduction to optical amplifiers 417 a raman amplifier is distributed over a long span of optical fiber. Wideband gain flattened hybrid erbiumdoped fiber amplifier. If an active region with a gain coefficient g and small length is considered, the initial photon density passes through the active region will increase by as illustrated in fig. Pradhan andabhilashmandloi departmentoferonicsengineering,sardarvallabhbhainati onalinstituteoftechnology svnit,surat,garat,india correspondenceshouldbeaddressedtodipikad. Optical amplifier archives tutorials of fiber optic products. Quantum electronics optical fibres and amplifiers related. Inline optical amplifier an overview sciencedirect topics. Experimental demonstration of a fewmode raman amplifier with. A narrow band optical filter is used to reduce transmission of amplified spontaneous emission frequency components.