Tecnología y Aplicaciones de la

Presentación del tema: "Tecnología y Aplicaciones de la"— Transcripción de la presentación:

1 Tecnología y Aplicaciones de la
Fibra Óptica Lucent Technologies Lucent Technologies, previously Western Electric and then AT&T Network Systems, has been providing telecommunication solutions to our customers for over 140 years, beginning with the telegraph in We have been at the forefront of fiber optic technology, beginning with the invention of the laser by Bell Laboratories in This presentation, Optical Fiber Technology and Applications, will give a brief overview of selected topics in the area of Fiber Optics. Lucent Technologies’ patented TrueWave® fiber was the first fiber developed to take full advantage of the latest technologies for increasing the transmission capacity and reducing the cost of fiber optic routes. These technologies are high bit rate time division multiplexing (TDM), erbium-doped fiber amplifiers (EDFAs), and dense wavelength division multiplexing (DWDM). NOTE: This presentation was scripted by Dan Geller from an original presentation by Jim Refi. I am very interested in any comments or additions you may have concerning this presentation’s visual or scripted content. Please send any comments to meat 1

2 Generalidades Propiedades de la Fibra Óptica
Distintos Tipos de Fibra Óptica Recomendaciones para la utilización de Fibra Monomodo o Multimodo Lucent Technologies Fibra Monomodo We will start with a general overview of the Optical Properties of fibers, to give you the background you will need to appreciate the more advanced topics. Next will be the recommendations by the International Telecommunications Union, an international standards setting body for fiber optics, for single-mode fibers and their applications, followed by Lucent Technologies offerings of these fiber types. Then we will discuss polarization mode dispersion, how it can affect light transmission, and what we have done to overcome this obstacle. And finally a summary of the topics we have discussed. 2

3 Ventajas con respecto a otros conductores
Alta Capacidad de Transmisión. Alta Velocidad de Transmisión. Seguridad. Bajo Peso. No Requiere Mantenimiento.

4 ESPECTRO ELECTROMAGNETICO
Radio de Onda Corta Sónico Ultrasónico Radiodifusión AM Radio /TV FM Radar Luz Infrarroja Luz visible Ultraviolera Rayos-X Rayos-Gamma Rayos-Cósmicos Frecuencia 18 21 1 Khz 1 MHz 1 GHz 1 THz 1000 THz Hz Hz Long. de onda Vel. Luz Frecuencia 100 Thz 1000 Thz INFRAROJA ULTRAVIOLETA 1550 nm 850 nm 400 nm 1300 nm FIIBRAS OPTICAS 1

5 Construcción Básica de la Fibra Óptica Multimodo
Cladding 125um Core 62.5um Coating 250um Data Transmission Concepts for Optical Fibre As an alternative to copper wire, optical fibre offers the following advantages: Support for higher data transmission rates Longer transmission distances Greater immunity to attenuation and Crosstalk Increased transmission capacity (greater bandwidth) In the past, higher costs have been a stumbling block for the use of optical fibre. These higher costs were not just for the cable, apparatus and installation, but also for the fibre electronics required. New developments in fibre products have enabled fibre to become more competitive with copper, particularly for high performance Local Area Networks (LANs). The increased transmission distances and capacity offered by fibre provide network planners more flexibility when designing their networks. This increased flexibility can lower the system price and operating costs by reducing the number of resources required to maintain the network. As data rates continue to climb and network designs become more complex, we can expect to see increased usage of optical fibre for these types of applications.

6 Construcción Básica de la Fibra Óptica Monomodo
Cladding 125um Core 6 a 9 um Coating 250um Data Transmission Concepts for Optical Fibre As an alternative to copper wire, optical fibre offers the following advantages: Support for higher data transmission rates Longer transmission distances Greater immunity to attenuation and Crosstalk Increased transmission capacity (greater bandwidth) In the past, higher costs have been a stumbling block for the use of optical fibre. These higher costs were not just for the cable, apparatus and installation, but also for the fibre electronics required. New developments in fibre products have enabled fibre to become more competitive with copper, particularly for high performance Local Area Networks (LANs). The increased transmission distances and capacity offered by fibre provide network planners more flexibility when designing their networks. This increased flexibility can lower the system price and operating costs by reducing the number of resources required to maintain the network. As data rates continue to climb and network designs become more complex, we can expect to see increased usage of optical fibre for these types of applications.

7 Fibra Óptica Monomodo/Multimodo Definición y Aplicaciones
Cladding Fuente Detector Fuente Detector Core Multiples haces de luz Unico haz de luz Bajo costo de emisores LED’s de hasta 622 Mbps Lasers de 155 Mbps hasta 1 Gbps Bajo costo de conectores. Alto costo de la fibra. Bajo costo del sistema. Alta pérdida y bajas longitudes de onda. Distancias de hasta 2 km. 225m - 550m con Gigabit. Corto alcance, Campo. Alto coso de emisores Lasers de 10 Gbps 400 Gbps + w/ DWDM Alto costo de conectores. Bajo costo de la fibra. Alto costo del sistema. Baja pérdida y altas longitudes de onda. Distancias de + de 60 KM. Largo alcance,campo,redes públicas. Fibre Optic Technology Structured cabling systems commonly use single and multimode optical fibre. Applications can therefore be supported over longer distances and in virtually any type of customer environment. 62.5/125 m Fibre The enhanced multimode (62.5/125 m) lightguide fibre is recommended for all premises applications because of its compatibility with the physical and transmission characteristics of the electro-optical devices commonly used in the premises distribution environment. The large core diameter and transmission characteristics of 62.5/125 m fibre offers the following advantages: Greater light coupling efficiency Less critical core alignment requires fewer administration points and splice locations Less susceptibility to micro and macro bending losses FDDI standard compliant ISO/IEC IS 11801, EN and ANSI/TIA/EIA-568A compliant 8.3/125 m Fibre Single-mode fibre was initially developed to support the high bandwidth and channel capacity needed in the long- haul trunk environment. Single mode fibre is an alternative for Campus environments of up to 3 km. and for high performance applications. For Gigabit applications and above, LED devices cannot be used and lasers will be the preferred transmitting device. This will drive the increased need for single mode cable.

8 Parametros de la Fibra D » n – n b a n D n
Technical Aspects of Fibre Optics For multimode and singlemode fibre, there are three primary design parameters which influence fibre performance. As shown in the fibre cross-section, these parameters are the core diameter (a), the cladding diameter (b), and the normalised difference in refractive index between the core and cladding (Delta). The is theoretically related to the numerical aperture (NA). It is important to know which values of NA are quoted, and the relationship between the two. Each of the fibre design parameters a, b and Delta (or NA), influences the performance and cost of a fibre. In addition, two secondary parameters - refractive index profile shape and profile smoothness - influence the fibre band performance. D » n 1 – n 2 a n 1 D n 2 n = Fase del índice de refracción

9 Principios de Operación
Fibra Multimodo/ Monomodo Principios de Operación Multimodo Cladding (Puro Sílice) Core (Sílice Dopado con Germanio) Índice de refracción- Monomodo Índice de refracción- An optical fibre is a strand of glass as thin as a human hair. It is designed to carry information using pulses of light emitted by a laser. Although it sounds relatively simple, optical fibre is actually a complex structure. It consists of three layers: Core: The glass in the centre of the fibre, and the region through which the light pulses travel. Cladding: The glass that surrounds the core and keeps the light from escaping the core. Coating: A layer of a soft, plastic-like substance, which surrounds and protects the glass fibre Core and cladding are both made from ultra-pure glass, but the cladding is actually more pure than the core. That's because when fibre is made, a substance called a "dopant" is added to the core glass to change its light- guiding properties. It is the difference in properties between the two glasses that keeps the light pulse contained in the core. It creates a glass tunnel of sorts (although the centre is not hollow) through which the light travels; when the light within the core interacts with the glass of the cladding, it reflects back into the core. This principal, called "total internal reflection," keeps the light trapped in the core and allows it to "bend" around curves in the fibre. In this manner, light signals can travel distances in excess of 100 miles before they need to be boosted. The pulses of light carry information through fibre using a binary code -- the pattern of "on" and "off" that determines what information the signal contains. It's something like the concept behind Morse code, where each series of pulses represents a letter of the alphabet. But with fibre, the pulses can be translated into voice, video or computer data, depending on the type of transmitter and receiver being used. La interface de Core/Cladding actúa como un espejo…. …. Resultando en una reflexión interna.

10 Distintos Tipos de Perfil de Fibra Multimodo
Indice de Refracción Escalonado Indice de Refracción Gradual

11 Indice de refracción de fibras Lucent G.652
Matched Clad (Ind.adaptado) Depressed Clad (Ind.reducido) n1 n1 8.3 mm 0.34% 8.3 mm 0.30% n2 silica -0.09% n3 46 mm These graphics show the index profiles of Lucent G.652 fibers. The index profile is the cross sectional view of the profile of the index of refraction of the fiber. Light travels fastest in a vacuum, and slower in any other medium. If you put a pencil in water, the pencil appears to bend at the surface of the water. This is because the speed of light in air is faster than the speed of light in the water, and the light is refracted. Refraction is the property that that we control to make eyeglasses and telescopes. We bend the light at the interface of the glass and air so that we can magnify images. In optical fibers, we want the light to stay in the center of the fiber. Light travels in a straight line, but the fiber has curves, so we create a difference in the index of refraction between the inner core and outer clad of the fiber so that the light will be continually bent back towards the center of the fiber, and we will lose as little light as possible. This is why we have this kind of index of refraction profile for these fibers. Both matched and depressed clad fibers are manufactured so as to have the minimum light loss when the fiber is bent. Their optical properties differ slightly, and different customers prefer different fibers for different reasons, and so at Lucent Technologies we manufacture both types of fibers so that our customers can get the specific type of fiber they prefer for their telecommunications systems. n = Fase de indice de refracción = Fase de velocidad en el vacio Fase de velocidad en el vidrio 12

12 Indice de Refracción de las Fibras Lucent G.653 y G.655
silica 6 mm 0.75% Dispersión desplazada (G.653) y TrueWave (G.655) Here we see the index profiles of Dispersion shifted and TrueWave fiber. The index profile of Dispersion Shifted and TrueWave non-zero dispersion fiber is much different than that of matched clad or depressed clad fiber that we saw in the last graphic. This is because we have altered the index of refraction so that the zero dispersion wavelength has been shifted away from the normal dispersion wavelength of glass, which is 1310 nm. We have shifted the zero dispersion wavelength to the 1550nm region to take advantage of the lower attenuation at that region. We can also take advantage of Erbium Doped Fiber Amplifiers (EDFAs), which only operate at the region of wavelengths around 1550 nm. 13

13 Pérdidas en el enlace Óptico
Esparcimiento Interno Acoplamiento de la Fibra a la Fuente Microcurvaturas/Macrocurvaturas Pérdidas de Interconexión The total path attenuation between the transmitter and receiver is the summation of the loss contributors: scattering, source-to-fibre coupling, microbending, macrobending and interconnection. The effect of source-to-fibre coupling occurs only once at the front end of a system, whereas the total scattering and microbending terms (dB/km) continuously erode this coupled power as a function of length. Macrobending loss is dependent on the installation environment, and the interconnection loss depends on the number of connections in the link. When these loss contributors are summed, the total link loss is a function of length and the number of connections. Hence different fibre design will optimise attenuation for different network configurations. The challenge is to choose a fibre with good performance over a wide range of system characteristics which satisfies both the present objectives and future upgradability requirements. Of the four attenuation factors, the source-to-fibre coupling efficiency and the susceptibility to bending induced losses provide the most distinction between fibre designs in practical multimode systems, with bending induced losses being important for singlemode systems. Differences in scattering losses among designs are small (on the order of tenths of a dB/km). Similarly, with the present much improved connector and splice technology, which is capable of consistently producing interconnection losses of 0.3dB or less, the practical difference in connector and splice losses among the fibre designs are small. For different fibre designs, the coupled power increases with both core diameter and Delta. Both microbending and macrobending losses increase directly with core diameter and inversely with Delta. From an attenuation perspective, the 62.5/125m fibre has the best overall combination of parameters for multimode systems, including relatively high coupled power and minimum sensitivity to both microbending and macrobending losses. Single mode systems inherently have lower loss depending upon the wavelength of operation. Other system variables such as bandwidth and cost must be considered.

14 Fibra Monomodo/Multimodo Principio de Operación
La energía del as de luz se refracta por el núcleo…... …pero mucha energía se pierde si los radios de curvatura son pequeños. Core Cladding Radio de curvatura Bending Induced Losses The power coupled into the fibre core is attenuated as it propagates along the fibre by scattering, as discussed above , and by microbending and macrobending induced losses. A microbend is a local deflection of the fibre axis with an amplitude much less than the fibre diameter. A ray of light propagating within the core will remain confined to the core unless microbends are sufficient to cause it to strike the core-cladding interface at an extensive angle, which allows the ray to escape and increase loss. Several factors can contribute to microbending induced loss, including glass non-uniformity at the core-cladding boundary and polymer coating irregularities, as well as packaging, installation and environmental effects. A macrobend is a bend or loop in the fibre with a radius of curvature of several millimetres or more. The effect of macrobends is to cause power to be lost from the core and thereby induce additional loss. Macrobends are encountered in splice cases, termination cabinets or any other point where the fibre encounters sharp bends or turns. Microbending and macrobending losses are important in distinguishing the fibre designs, generally the smaller the optical aperture the more sensitive the fibre is to these losses. El proceso de instalación es importante Mantener los radios de curvatura mínimos

15 Atenuación en F.O. Monomodo/Multimodo
Enlace de Fibra Óptica Emisor Receptor Pérdida en Db Cable/Conector Energía de entrada Energía de salida Attenuation Attenuation of optical fibre is much lower than for copper cable, usually expressed in dB/km. The loss depends on the wavelength of the light used for the optical transmission. The total attenuation of the optical signal between transmitter and receiver determines the maximum system length and the number of connections allowed. There are four attenuation mechanisms that depend on the fibre design parameters. La energía de salida es pequeña, el enlace falla. El receptor no puede detectar la señal óptica

16 Fibra Óptica Tecnología de conexión
La buena alineación de los núcleos de la fibra permiten una eficiente transmisión de la energía entre ellas. Base de Ferrule: es la conexión más usada y rentable Vista lateral - Corte transversal Conector (Backbone) Ferrule cerámico Fibra Interconnection Loss Interconnection loss associated with splices and connectors can be divided into two components- intrinsic and extrinsic. Intrinsic mechanisms are a direct function of manufacturing tolerances on fibre core diameter, ovality, eccentricity and Delta. Extrinsic mechanisms depend on the connection hardware and its ability to control separation between the fibre ends, axial tilt and fibre transverse offset normalised to core diameter. Total interconnection loss is the sum of the intrinsic loss and all extrinsic effects. It is not uncommon to find higher interconnection loss with a larger core fibre (compared to a smaller fibre) due to looser fabrication tolerances which lead to more intrinsic loss. Guía de alineación

17 Representación del Conector Óptico
Baja energía ENTRADA SALIDA Pérdida de retorno/reflectancia Insertion loss Optical power loss caused by inserting an optical component such as a fibre, connector, or splice into an optical path. Most severe at connections, caused by Core Misalignment. Return loss/reflectance Ratio of reflected power to incident power Can cause “false” signals as power is reflected back and forth in link Primarily effects Broadband Video and Telecom links May effect future high speed digital data links Guía

18 Atenuación de las Fibras
Microcurvaturas. Absorsión. Dispersión.

19 Atenuación de las Fibras
Microcurvatura (Esfuerzo) Dispersión Impureza Absorsión

20 Atenuación en la Fibra Óptica multimodo
These are the windows of operation 1st window 850 nm 2nd window 1300nm 3rd window 1550nm these are all in the infrared spectrum Longitud de onda

21 Atenuación de la Fibra Monomodo
0.6 Ventanas de operación 0.5 0.4 Atenuación (dB/km) 0.3 0.2 This is a basic plot of the attenuation of a typical single mode fibre, with the attenuation, measured in decibels per kilometre on the left hand side of the graph, and wavelength, measured in nanometres (nm), along the bottom. A decibel (dB) is a unit of loss, or attenuation, which uses a logarithmic scale. If the output of the fibre was 1/10 the input, the loss would be 10dB, and if the output was 1/100 the input, the loss would be 20dB. A nanometre is a unit of length measurement, with 1,000,000 nanometres per millimetre. The visible light spectrum, for example, is 410 nanometres (violet) to 650 nanometres (red). What we see in this plot is that single-mode fibre has low loss in two different operating windows: the 1310 and 1550 nanometre windows. The 1310 nm window was first used because some of the early lasers operated at that wavelength. Now the 1550 window is used for various reasons, including the lower loss at that window, and that Erbium Doped Fibre Amplifiers (EDFAs) can be used there. EDFAs operate in the lowest loss region of an optical fibre--the 1550 nm window. Many transmission systems today operate at 1310 nm where the fibre's loss is about 0.34 dB/km. Because the fibre's attenuation is lower at 1550 nm, and because EDFAs operate in the 1550 nm window, there is a trend for newer systems to operate at the longer wavelength. 0.1 1100 1200 1300 1400 1500 1600 1700 Longitud de onda (nm)

22 Valores Tipicos de Atenuación en Fibras Opticas Multimodo

23 Valores Tipicos de Atenuación en Fibras Opticas Monomodo

24 Fibra Multimodo - Dispersión modal
Ensanchamiento del pulso Límite del ancho de banda Cladding EMISOR DETECTOR Core Bits superpuestos = Error de Bit ENERGÍA Modal Dispersion In multimode fibre the dispersion is caused by modal dispersion. Modal dispersion exists because the different light rays (modes) have a different path length, therefore rays entering at the same time will not leave the fibre at the same time at the other end of the fibre. The modal bandwidth is controlled by the pulse broadening due to the differences in group velocities for the many propagating modes (300 to 900). In general, the modal bandwidth of a multimode fibre decreases with increasing , due to the increasing number of propagating modes. The Multimode fibres have a layered structure that reduces the effect of the modal dispersion. These fibres, called graded index fibres, are used in all SYSTIMAX SCS Multimode fibre products. With Multimode fibre transmission distances of up to 2 km. are possible. When used inside only the maximum operating frequency for lengths up to 300 m. is about 2.5 Gbit/s. For singlemode system, the method for fibre transmission is to reduce the core glass diameter to a size where only one ray (mode) can propagate through the fibre. The modal dispersion is no longer present. Dispersion in a Single mode fibre is chromatic dispersion, caused by the lightsource, which is not fully monochromatic. Single mode fibre presents higher system cost. The fibres are less expensive, the connection materials must have a higher accuracy and are therefore more expensive. The light sources must have a narrow beam in order to couple in light in this type of fibre. Inexpensive LED light sources can not be used, the more expensive Lasers must be used. The higher cost of active equipment makes Multimode systems more cost-effective than Single mode in most premises applications today. TIEMPO Tren de Pulsos de Entrada Tren de Pulsos de Salida

25 Dispersión - Ancho de banda
Sección del Pulso de Propagación de Pulso de Sección transversal índice de entrada la luz en la fibra salida refracción Tipo : índice escalonado multimodo r A 125 um 100 um n r Tipo : índice gradual multimodo r A 125 um 50um n r This slide explains the difference between multimode and singlemode, step index and graded index fibre and how dispersion is the limiting factor for bandwidth. Bandwidth The bandwidth of the fibre determines the maximum rate at which information can be transmitted through the network. The bandwidth of fibre can be divided into two main components - modal and chromatic - and both contribute to the total bandwidth. Crosstalk does not occur in the fibres itself, the bandwidth of fibres is mainly limited by their dispersion. Depending whether it is singlemode or multimode, the system performance is determined to different degree by the combined effects of modal and chromatic dispersion. For Single mode systems, other factors such as Polarisation Modal Dispersion and Non-Linear Effects must be considered, but these are more apparent for long distance transmission systems. Tipo : Fibra monomodo r A 125 um 10um n r

26 Atenuación y Dispersión de Varias Fibras
0.6 G.652 20 10 -10 -20 0.5 EDFA band 0.4 Atenuación (dB/km) Dispersión (ps/nmùkm) 0.3 G.655 0.2 0.1 This plot shows the attenuation of a single mode fibre, which we saw before, and also shows the dispersion of the various types of single mode fibre. The attenuation is on the left axis, and the dispersion is on the right axis. The units of dispersion are picoseconds per nanometre kilometre. This means the delay time (in picoseconds) if one nanometre width of light is transmitted one kilometre. The delay would be the total time from when the light began to be received to when it finished being received. Fibres G.652 (matched clad and depressed clad) has the zero dispersion wavelength at 1310 nm, and this is the wavelength at which it is usually used. Fibre type G.653 (dispersion shifted) has its zero dispersion wavelength at 1550 nm, and again, this is the wavelength at which this fibre is usually used. The new fibre (non-zero dispersion shifted) has a small amount of dispersion at 1550 nm, and the reason for this will be explained later. EDFAs operate in the lowest loss region of an optical fibre--the 1550 nm window. Many transmission systems today operate at 1310 nm where the fibre's loss is about 0.34 dB/km. Because the fibre's attenuation is lower at 1550 nm, and because EDFAs operate in the 1550 nm window, there is a trend for newer systems to operate at the longer wavelength. 1100 1200 1300 1400 1500 1600 1700 Longitud de onda (nm) 8