Dispersion management is the process to design the fiber and compensating elements in the transmission path to keep the total dispersion to a small number. Certified that this project report titled analysis of dispersion compensation techniques and fiber nonlinear effects in dwdm optical networks is the bonafide work of sathya. In proposed work we have provided a fbg system to transmit lossless data up to 80 kilometer. Design and simulate a fiber optic system using dispersion compensating fiber to reduce chromatic dispersion. A multiclad fiber with a triangular refractiveindex profile in the core gives a dispersion of. Polarizationmaintaining dispersioncompensating optical fiber. The use of dispersion compensating fiber is an efficient way to upgrade installed links made of standard single mode fiber 2. As a consequence of its optical characteristics, the chromatic dispersion of a fiber can be changed by acting on the physical properties of the material. How does a dispersion compensating fiber reduce chromatic. Characteristics dcf fbg bandwidth 20 nm wide band, 0. There are three main types of dispersion in a fiber. The isi thus limits transmission of high speed data. Pulse spreading due to the dispersion causes the overlapping of the transmitted pulses at the receiver end known as inter symbol interference isi.
With the development of wavelength division multiplexing wdm techniques for large capacity optical communication systems, dispersion compensation technologies have been applied into the field. In fiber optic communication is transmitted pulses of light through an. Dispersion managed fiber dmf designs were introduced where the dispersion slope was also compensated. The dispersion of smf in the 1550nmwavelength is 17 20 ps with positive dispersion slope. The following shape was generated in the optical gaussian pulse generator with an initial 12. Dispersion phenomena in optical fibers halina abramczyk. Performance analysis of dispersion compensation in long haul. The bitrates must be low enough to ensure that pulses are farther apart and therefore the greater dispersion can be tolerated.
A photonic crystal fiber based on a particular periodic arrangement of airholes and pure silica is designed for chromatic dispersion compensation. There is an assumption for the proposed structure to keep the 1 st mode in a central core over the wide working spectrum of. Dispersion adjustment broad band dispersion compensating of dwdm network and extremely low residual dispersion 80120% slope compensation in cl band low insertion loss and high negative dispersion coefficient high figure of meritfom low pmd performances meet the criterion telcordia gr2854core reliability meets the criterion telcordia. The dispersion compensating fiber dcf is tested for a single span, single channel. Dispersion compensation was originally proposed to equalize pulse distortion. Negativedispersion optical fiber and optical transmission line incorporating the same. Here, strong dispersive broadening of modulated signals can occur in cases with high data rates. Regenerators, however, are not generally designed to compensate for chromatic dispersion, this is routinely achieved using dispersion compensating fiber dcf. Inverse design of dispersion compensating optical fiber. Dispersioncompensating fiber in doubleclad fiber for dispersion compensation, the inner cladding layer has lower refractive index than the outer layer. This dispersion compensation fiber dcf is designed to compensate the accumulated dispersion in long haul optical fiber transmission systems in the c band.
Each repeater span basically consists of two kinds of fibers. With the program optisystem, is simulated the dispersion compensating of a link of optical fiber communication system using dcf and cfbg with different apodizations. If a transmission fiber of length l tf is connected in series with a dcf of length. According to the relative positions of dcf and single mode fiber the three dispersion compensation schemes predcf, postdcf and symmetrical mixdcf are proposed. Dispersion compensating fiber and optical transmission system including the same. Static and tunable dispersion compensation modules for access, dci and legacy communication systems. Dispersion compensating fibers dcfs are quite attractive fiberbased. Fiber brag grating fbg and dispersion compensating fiber dcf are two mostly used techniques in long haul communication. Dispersion compensation is an important issue for fiber optic links, i.
The extra dispersion used to encrypt and hide the stealth channel can be achieved by adding the extra length of standard single mode fiber ssmf, dispersion compensation fiber dcf, chirped fiber bragg grating 6, or photonic crystal fibers 7. Optimum fiber design and properties of different fiber combinations are treated. Dispersion compensating fiber has a high negative dispersion 70 to 90 psnm. Singlemode dispersion compensating fiber designs with absolute dispersion values of greater than 100 psnm km are described. Fiberbased dispersion compensation is an attractive technology for upgrading wdm communication. Osa design of dispersioncompensating fibers based on a. Then, the total dispersion equation can be rewrite as 3 2. Project layout for dispersion compensation with fiber bragg grating component in optisystem the following shape was generated in the optical gaussian pulse generator with an initial 12. This type of fiber is also called depressedinnercladding fiber and wprofile fiber from the fact that a symmetrical plot of its refractive index profile superficially resembles the letter w. The ape femtocontrol is a compact motorized dispersion compensation unit for.
We are living in the age of bandwidth hungry and high speed applications, for which optical networks form the most important part because of its high bandwidth. Dispersion compensating fibers for raman applications. Single mode dispersion compensating fiber aitc group. In view of optical properties for transmission system, production cost, and module assembly, for a long time slope compensating and dispersion compensating fiber scdcf has been the most advantageous and widely used method as dispersion compensation devices. In this technique, the designed wdm system is compensated with dispersion compensating post compensation method in which dcf is used after the non linear fibre. A simulation approach for dispersion compensation in. Material dispersion occurs because the refractive index of cladding changes with the wavelength and waveguide dispersion due to light confinement problem in the fiber core, where the light is also propagated through the fiber cladding that travel at different velocities. To reduce fiber dispersion, new types of fiber were invented, including dispersionshifted fibers itu g.
The amount of light dispersed by a normal fiber in reduced or even nullified by using a dispersion compensating fiber having a very large value of dispersion of opposite sign as. Fiber dispersion and optical dispersion an overview. Dispersion limits the bandwidth or information carrying capacity of a fiber. A slopecompensating rate can be expressed by the following equation using rds. Thorlabs offers dispersion compensating bare fiber for custom solutions across a broad spectral range in the telecom region. Dispersion compensation techniques for optical fiber. In this paper, the performance of high speed optical fiber based network is analysed by using dispersion compensating module dcm. Dispersion deployment and compensation for optical. Dispersion management using dcf dispersion compensation fiber. Low loss chromatic dispersion emulators and compensators available for lab use. The splice loss between dcf and standard fibers is shown to be reducible by use of a special intermediate fiber. A dispersion compensating module or dcm is used to compensate the cumulative dispersion in a single mode fiber and a dispersion coefficient is used to characterize the dispersion value. We have used coupled mode equations to evaluate appropriate fbg profile for long distances. Rp photonics encyclopedia dispersion compensation, pulse.
Singlemode optical fiber having multiple cladding regions for dispersion compensation. Dispersion techniques dispersion compensating fibers fiber bragg grating electronic dispersion compensation digital filters optical phase conjugation techniques 7. Use of dispersion compensating fiber in optical transmission. Is also analysed the cfbg the apodized and nonapodized using the program optigrating. A slope compensating and dispersion compensating fiber scdcf utilizing a. Dispersioncompensating fiber an overview sciencedirect topics. Dispersion compensation using only fiber bragg gratings article pdf available in ieee journal of selected topics in quantum electronics 55. Analysis and simulation of dispersion compensation in.
Pdf symmetrical dispersion compensation for high speed. Dispersion compensating optical fiber, and wavelength division multiplexing transmission line using a dispersion compensating optical fiber. The first type spliced to the repeater output is a large effective area fiber with positive dispersion. Standard single mode fiber or nonzero dispersion shifted fiber has been widely used in long haul systems. Rp photonics encyclopedia dispersionshifted fibers. Dispersion compensating fiber dcf provides an optical medium with a relatively large negative chromatic dispersion factor d. Dispersioncompensating fiber an overview sciencedirect. The length of non linear fibre is 75km with dispersion of 0. Dispersion compensating fiber and optical transmission system including the.
A twoconcentriccore structure is obtained by introducing two different sizes of capillaries for the airholes and exhibits very high negative chromatic dispersion 2200 psnm km at 1550 nm. Dcf modules inserted into transmission line at regular interval. In this paper, the use of chirped fbg has been studied as a dispersion compensator in an optical communication system. The rp photonics buyers guide contains 20 suppliers for dispersion compensation modules. The optimal operating condition of the dcm is obtained by considering dispersion management configurations for the symmetrical system i. Dispersioncompensating fiber dcf provides an optical medium with a relatively large negative chromatic dispersion factor d. Several techniques, including dispersion compensating fiber or fiber bragg grating, can be used to compensate the accumulated dispersion in the fiber. Conventional dispersion compensating fibers have a high negative dispersion 80 psnm. Dual core dispersion compensating fibre with large negative dispersion parameter a concentric core dcf based on microstructured optical fibre is proposed 1. Compensation of dispersion at a wavelength around 1550nm in a 10nm optimized single mode fiber can be achieved by specially designed fibers whose.
Dispersion compensation optical fiber modules for 40 gbps. The idea of using dispersion compensation fiber for dispersion compensation was proposed as early as in 1980 but, until after the invention of optical. The key optical properties of scdcf are chromatic dispersion, rds, figure of merit fom, bending loss, cutoff wavelength, and effective area aeff. The importance of matching not only the dispersion and dispersion slope but also the dispersion curvature has been demonstrated with a new dispersion compensating fiber for low slope nzdf with rds.
So far, several dispersion compensation techniques have been proposed. A simulation approach for dispersion compensation in optical. The dispersion arrangement, which considers both the second and third order dispersion characteristics is illustrated in the above figure. Dispersion can cause various penalties in signal transmission in optical communications systems. This is largely because groupvelocity dispersion gvd, or socalled chromatic dispersion cd, in optical fibers i. Dispersion compensating optical fiber for smf and transmission link including same. Analysis and simulation of dispersion compensation in fiber. First we will use dispersion compensating fibers dcfs. Dispersion compensating fiber dcf, chirped fiber bragg grating cfbg, optigrating, optisystem, dispersion compensating, apodization. Optical fiber for compensating the chromatic dispersion of an optical fiber having positive chromatic dispersion. Dcf3 fiber is a nonzero dispersionshifted fiber nzdsf with negative dispersion and low positive dispersion slope that is optimal for medium distances and wide band wdm systems. A dcf is a fiber that causes dispersion opposite to conventional singlemode fibers. Analysis of dispersion compensation using fiber bragg.
Ask rp photonics for finding the most suitable dispersionshifted fiber for your application definition. Dcf can minimize the overall dispersion to optimize the system for high bit rate. Polarization mode dispersion compensation in wdm system. Typically, devices used to generate large amounts 100 psnm of chromatic dispersion are based on diffraction gratings, chirped fiber bragg gratings, or dispersion compensating fiber. Dispersion compensation schemes a system perspective.
Design and simulate a fiber optic system using dispersioncompensating fiber to reduce chromatic dispersion. In view of optical properties for transmission system, production cost. The ability to control chromatic dispersion is paramount in applications where the optical pulsewidth is critical, such as chirped pulse amplification and fiber optic communications other devices. Pdf dispersion compensation in an optical fiber by using chirp gratings esat journals academia.
Dispersion compensation fiber dcf, with its large negative cd coefficient, can be inserted into the link at regular intervals to minimize its global chromatic dispersion. Thus, dispersion management is a very important part of designing a fiber optic transmission system. Pdf performance analysis of dispersion compensation in long. Dispersion compensating fiber dcf in dispersion compensating fiber technique we use a fiber having a large negative dispersion along with a standard fiber. Research on dispersion compensation of 40 gbs optical duo. High performance dispersion and dispersion slope compensating. Dcf3 fiber is a nonzero dispersion shifted fiber nzdsf with negative dispersion and low positive dispersion slope that is optimal for medium distances and wide band wdm systems. Different dispersion compensation techniques in fiber. Inverse design of dispersion compensating optical fiber using.
Alternative methods for dispersion compensation which have been proposed include chirped bragg grating, etalons and ring resonators, to name a few. Mar 08, 2019 intramodal dispersion in optical fiber pdf admin march 8, 2019 march 8, 2019 no comments on intramodal dispersion in optical fiber pdf due to dispersion when the optical pulses travel along the fiber they broaden as shown in 1 intramodal or chromatic dispersion present in single mode an. Note how an open transmit eye from which correct decisions can easily be made, begins to close due to dispersion and noise, as the distance through the fiber increases. Fiber dispersion and optical dispersion an overview fosco. The use of dispersion compensated fiber dcf is considered as the best method to mitigate harmful.
The overall dispersion of these fibers is opposite in sign and much larger in magnitude than that of standard fiber, so they can be used to cancel out or. The chromatic dispersion of a fiber is expressed in psnmkm, representing the differential delay, or time spreading in ps, for a source with a spectral width of 1 nm traveling on 1 km of the fiber. Starting with the basic principle behind dcf, its need for upgrading the 10 nm optical fiber links is discussed. It depends on the fiber type, and it limits the bit rate or the transmission distance for a good quality of service. Compensation of dispersion with fiber bragg grating component. Dispersioncompensating fiber how is dispersioncompensating fiber abbreviated.
This means that the dcf should match not only the dispersion, d, but the dispersion slope, dd fiber d. Broadband dispersion compensation technology in high speed. Fiber bragg grating fbg is one of the most applicable components to compensate dispersion losses in optical communication system. Pdf dispersion compensation using only fiber bragg gratings. Performance analysis of dispersion compensation in long haul optical fiber using dcf. Performance analysis of dispersion compensation in long. Dispersion compensation in optical fiber communication. Project layout for dispersion compensation with fiber bragg grating component in optisystem.
All fiber designs use only the fundamental lp01 mode for dispersion compensation and can account for first and. Optical fiber with highly negative dispersion at 1550nm to compensate for a buildup of positive dispersion in that region in conventional fiber. When shining a beam of white light into a prism, you see the light is composed of a rainbow band. In order to achieve high speed, large capacity and long distance communication, it is necessary to use dcf in the optical fiber 7, thus the total dispersion of the whole optical fiber line is approximately zero 8. In this paper, dispersion compensating fibers dcf are used to compensate the positive dispersion accumulated over the length of the fiber at. The dispersioncompensating fiber should be selected to match the dispersion of a regular sm or pm fiber, not only at a single wavelength, but over the whole spectral range of the optical pulse. A fiberoptic technique for compensating both first and secondorder groupvelocity dispersion in singlemode fiber spans is demonstrated by using the large waveguide dispersion that occurs for. Ajout dun anneau externe au profil dindice dune fibre optique monomode a dispersion decalee. No matter what your link dispersion looks like there is a solution with our continuous fbg dcms. Since dispersion is inevitable in optical fibers, dispersioncompensating fibers, such as those sold on this page, can be incorporated into optical systems. Using these dispersion compensation modules, the transmission distances in fiber can be increased significantly without regenerating the signals. Dispersion compensating fiber module semantic scholar.
Apr 21, 2018 historically, singlemode optical fiber was designed with the minimum chromatic dispersion point at the operating wavelength. In the following example we will show three different schemes, pre, post, and symmetrical compensation, to compensate the fiber dispersion. Typically, dispersion compensating elements are placed every 100 km or so. For instance, if smf has positive dispersion over a specific range of wavelengths, dcf has negative dispersion over the same.
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