EDFA – Amplificateur à fibre dopée à l’erbium

Erbium-doped fiber amplifier (EDFA) is the first profitable optical amplifier invented via the UK Southampton University and JP Tohoku University. It is one of the biggest invention in optical communication. Erbium-doped optical fiber is integrated a small quantity of a uncommon earth aspect erbium (Er) ion. It is the core of the EDFA. From the late 1980s, the EDFA lookup has been making a most important step forward continuously. As WDM science radically will increase the ability of optical communication, it will become the most broadly used optical amplifier machine in the optical fiber communication.

EDFA is constituted through a duration of erbium-doped fiber (about 10-30m) and pump mild source. The encouraged emission of erbium-doped fiber below the motion of the pump mild supply (wavelength 980nm or 1480nm), and the radiation of mild varies with the exchange of the enter optical signal, which is equal to the enter optical sign the amplification. Studies have proven that the erbium-doped fiber amplifiers are usually 15-40dB of obtain can be obtained, and the distance relay can be accelerated on the foundation of the authentic extra than 100km. So, why did scientists use erbium-doped fiber factor to amplify the depth of light? We recognize that erbium is a form of uncommon earth elements, and uncommon earth factors has its specific structural features. Over the years, humans have been the usage of the approach which doped uncommon earth factors in optical units to enhance the overall performance of optics, so this is no longer an unintentional factor. In addition, why is the pump supply wavelength chosen from 980nm or 1480nm? In fact, the pumping mild supply wavelength may want to be 520 nm, 650nm, 980nm and 1480nm. But the exercise has proved that the 1480nm wavelength pumping mild supply laser effectivity is the highest, observed through the 980nm wavelength.

The essential benefit of EDFA is a excessive gain, huge bandwidth, excessive output power, excessive pumping efficiency, low insertion loss, and now not touchy to the polarization state.

Its amplifying region happens to coincide with the minimal loss vicinity of single-mode fiber. This reduces the transmission loss of the mild sign which can be transmitted enormously some distance distance.
It is obvious to digital sign layout and information rate.
Its amplification bandwidth is so vast that dozens or even thousands of channels can be transmitted in the equal fiber.
It has low noise determine shut to the quantum limit, which skill that a couple of amplifiers can be cascaded.
Its reap saturation restoration time is long, and has a very small crosstalk between the respective channels.

When EDFA is used in traditional optical digital verbal exchange gadget applications, we can store a lot of optical repeaters, and the distance relay should additionally be elevated significantly, which is of exceptional importance for the long-haul fiber optic cable trunking systems.

The fundamental functions include:

It can be used as the mild distance amplifier. Traditional digital fiber optic repeater has many limitations. Such as a digital sign and the analog sign conversion, the repeater have to be modified accordingly; repeater adjustments after the machine is modified from a low fee to a excessive rate; solely transmit the equal wavelength of the optical signal, and the complicated structure, expensive, and so on. Erbium-doped fiber amplifier to overcome these shortcomings, now not solely do now not have to alternate with the exchange in the way of the signal, and tools growth or for optical wavelength division multiplexing, no want to replace.

It can be used for the transmitter amplifier and the optical receiver preamplifier. For the rear of the optical transmitter amplifier, the transmit energy of the laser is extended from 0dB to +10 db. Optical receiver preamplifier, the sensitivity can additionally be appreciably improved. Therefore, solely the line of 1-2 erbium-doped amplifier, the sign transmission distance can be accelerated to 100-200km. In addition, the erbium-doped fiber amplifier trouble to be solved the special blessings of the erbium-doped fiber amplifier has been diagnosed by way of the world, and to be greater extensively used. However, the erbium-doped fiber amplifier there are additionally some limitations. For example, in the long-distance verbal exchange can now not drop channel, every station commercial enterprise contacts is extra difficult, now not handy to discover fault, pumping mild supply lifestyles is now not long, as the optical fiber verbal exchange technological know-how continues to progress, these troubles will be satisfactorily resolved.

Le guide du tricheur pour choisir des câbles de raccordement à f

Qu’est-ce qu’un câble de raccordement à fibre optique

Le câble de raccordement à fibre optique, régulièrement appelé ficelle de raccordement à fibre optique ou câble de raccordement à fibre optique, est un câble optique terminé par des connecteurs à chaque extrémité. Il dispose de deux zones utilitaires principales : poste de travail pour ordinateur portable vers prises et panneaux de brassage ou optique pour rejoindre le centre de distribution. Ils sont réservés aux fonctions intérieures.

Types communs

Les câbles de raccordement à fibre peuvent être divisés en types spécifiques basés entièrement sur le mode de câble, la structure du câble, les types de connecteurs, les types d’épiçage des connecteurs et les tailles de câble.

Mode câble :

1. Mode unique :

Les câbles de raccordement monomode utilisent un câble en vrac de 9/125 microns et des connecteurs monomodes à chaque extrémité. La gaine de la fibre monomode est généralement jaune.

2. Multimode :

Les câbles de raccordement multimodes utilisent une fibre multimode en vrac de 62,5/125 microns ou 50/125 microns et se terminent par des connecteurs multimodes à chaque extrémité. La gaine de la fibre multimode est généralement orange.

3. Multimode 10 gigaoctets :

Les fibres multimodes 10Gig sont en particulier des fibres 50/125 microns optimisées pour le laser VCSEL 850nm à base d’Ethernet 10Gig. Ils sont arriérés avec les outils communautaires actuels et fournissent près de trois instances la bande passante des fibres multimodes 62,5/125 habituelles. La gaine du câble fibre 10Gig est généralement aqua.

Structure du câble :

1. Câbles de raccordement simplex :

Le câble de raccordement Simplex a une fibre et un connecteur à chaque extrémité.

2. Câbles de raccordement duplex :

Le câble patch duplex a deux fibres et deux connecteurs à chaque extrémité. Chaque fibre est marquée “A” ou “B” ou des bottes de connecteur de couleur exceptionnelle sont utilisées pour marquer la polarité.

3. Assemblage du câble de sortance du ruban :

Pour l’assemblage de câbles de sortie de ruban, un arrêt est la fibre de ruban et le connecteur de ruban tel que le connecteur MTP (12 fibres), les différents arrêts sont plus d’une fibre avec des connecteurs tels que ST, SC, LC, etc.

Types de connecteur :

1. Même type de connecteur :

Ce type a le même type de connecteur à chaque extrémité, tel que ST, SC, LC, FC, etc.

2. Hybride :

Ce type a des connecteurs distincts à chaque extrémité. Un arrêt peut être SC et les différents arrêts peuvent être LC, ST, FC, etc.

Types de polissage de connecteur

Les connecteurs optiques sont conçus et polis selon des formes spécifiques pour limiter à nouveau la réflexion. Ceci est particulièrement vital dans les applications monomodes. Les niveaux de réflexion typiques renvoyés sont -30dB, -40dB, -50dB et -60dB.

1. PC (contact physique) : la réflexion typique du bas du dos est bien inférieure à -40 dB, pour les applications monomodes et multimodes.

2. UPC (Ultra Physical Contact) : la réflexion renvoyée typique est bien inférieure à -50 dB, pour les applications monomodes.

3. APC (Angled Physical Contact) : la réflexion typique est bien inférieure à -60 dB, pour les applications monomodes.

Sortes spéciales de câbles patch

1. Câble de raccordement de conditionnement de mode

Dans certains cas, comme pour les modules laser à ondes longues utilisés dans Gigabit Ethernet, les modules veulent fonctionner pour chaque fibre monomode et multimode, les câbles de raccordement à fibre optique de conditionnement de mode conviendront à de telles situations.

En permettant au lancement laser monomode d’être décalé du cœur de la fibre multimode, le câble de raccordement à fibre optique de conditionnement de mode réduit l’impact d’un tel retard de mode différentiel. Ces câbles sont généralement de type duplex.

2. Câble de patch de retenue de polarisation

Les câbles à fibres optiques à maintien de polarisation sont fabriqués avec une fibre unique qui continue la polarisation des ondes douces. Ils sont utilisés là où un équilibre excessif est requis, ne résistant plus aux mouvements des fibres et des contraintes.

Ces câbles sont généralement utilisés dans l’instrumentation, la dimension et dans certaines fonctions où la stabilité est requise à des vitesses supérieures à 10 Gbps.

How Much Temperature Can the Optical Fiber Withstand?

by http://www.fiber-mart.com

Is the fiber optical cable afraid of excessive temperature? Different kinds of optical fiber cables have an top limit. The working temperature of general optical fiber community cable is -40ºC ~ +75ºC.

If it is an optical fiber cable used in industry, every fiber cable has a one-of-a-kind composition, the excessive temperature and low temperature it can stand up to are different, so you want to seek advice from the producer for details.

The Optical fiber temperature regulation
The higher and decrease limits of the working surroundings temperature of the optical fiber cable temperature dimension device are typically -20℃~+55℃.

Generally, the traditional excessive temperature resistant optical fiber is -20°~+300° for long-term, and for momentary can attain 350°

The working surroundings temperature of the allotted optical fiber temperature size machine is -10℃~50℃, and the temperature size vary is traditional temperature: -40—120℃; excessive temperature optical cable: -40—400℃

The measuring temperature vary of optical fiber grating temperature sensor is -40℃~300℃

How Optical fiber cable is affected by using temperature?
1. The temperature attribute of optical fiber refers to the have an effect on on optical fiber loss beneath excessive and low temperature conditions. The loss of optical fiber will increase underneath low temperature conditions. This is due to the extraordinary growth coefficients of optical fiber coating layer, overmolding layer and quartz. The thermal growth coefficient of natural resin and plastic is tons large than that of quartz. It shrinks at low temperature and elongates at excessive temperature. Under the motion of this type of axial compressive force, microbending will amplify the loss. If working at low temperature, as the temperature continues to decrease, the fiber loss will proceed to increase. When the temperature drops to about -55°C, the loss will increase sharply, making the device unable to function normally.

2. The microbending loss of the optical fiber due to temperature modifications is brought about through thermal growth and contraction. It is regarded in physics that the thermal growth coefficient of the silicon dioxide (SiO2) that constitutes the optical fiber is very small, and it infrequently shrinks when the temperature drops. The optical fiber should be lined and introduced with some different elements all through the technique of forming a cable. The growth coefficient of the coating cloth and different factors is rather large. When the temperature decreases, the shrinkage is extra serious, so when the temperature changes, the enlargement coefficient of the cloth is different. , Will make the optical fiber bend slightly, specially in the low temperature area.

What are Features and Applications of Multimode Fiber Cables?

The data center has become the engine of modern life, and the growing network information is transmitted and stored at high speed through the data center. Most of the connection distances inside the data center are short, ranging from a few meters to a few hundred meters. In these short-distance high-speed data communications, multimode optical fibers and optical modules with vertical cavity surface emitting lasers (VCSEL) as the core components have been widely used. Compared with the single-mode transmission scheme, the multi-mode scheme uses a low-cost, low-power laser to achieve fast and efficient coupling between the fiber and the laser. Multi-mode fiber can achieve higher transmission rate or longer transmission distance than copper cable, and lower cost than single-mode fiber system.At present, the internal connection rate of the data center has reached 100 Gbit/s, and 400 Gbit/s is just around the corner. The industry has been developing new types of multimode optical fibers to improve its performance, including broadband multimode optical fiber technology that realizes wavelength division multiplexing in a single optical fiber; and long-wave multimode optical fiber that supports longer transmission distances. In addition, in order to support high-density, miniaturized connections, and improve data center space utilization, heat dissipation efficiency, and cable management efficiency, multimode optical fibers with bending resistance have also been rapidly developed and deployed. This article will combine the technical principles of multimode fiber and the evolution of optical module technology to discuss the development trend of multimode fiber supporting high-speed optical transceivers.

1. The Features and Applications of Multimode Fiber Cables

The development of cloud computing has promoted the development of ultra-large-scale data centers, resulting in a development trend different from traditional enterprise data centers. Whether it is domestic or international, the evolution of server port rates for ultra-large-scale data center users based on cloud computing services is significantly faster than that of traditional enterprise data centers. Traditional enterprises will stably use OM4 Multimode Fiber Cables, and more than 90% of the system link length is less than 100m.

However, ultra-large-scale data center users choose more singlemode fiber cables, and 70% of the system link length exceeds 100m.

The development of ultra-large-scale data centers has increased the utilization rate of single mode fiber cable, but multimode fiber cable still has its unique advantages. These advantages are that the use of lower-cost optical transceiver modules, lower power consumption, and the transmission distance can cover most of the links in the data center, so solutions based on Multimode Fiber Cables and multimode optical modules are still very attractive to customers.

2. The Bandwidth of 850nm Multimode Fiber Cable

Unlike the single mode fiber optic system, the transmission distance and speed of the multimode fiber optic system are limited by the bandwidth of the multimode fiber cables. In order to support the higher transmission distance of the high-speed system, the mode bandwidth of the multimode fiber cable needs to be increased. The design of multimode fiber cable usually adopts a-profile of graded index to reduce the mode group delay and achieve high bandwidth.

Among them, rO is the core radius, ∆0 is the maximum value of the relative refractive index change of the core, which can be expressed as follows.

Among them, nO is the central refractive index of the core and n1 is the refractive index of the cladding.

Choosing an appropriate value of a, the mode bandwidth of the multimode fiber optic cables can be optimized within a certain wavelength range. Figure 3 shows the bandwidth distribution of a 50 µm multimode fiber cable when there’s 1% change in the a value of the 850 nm wavelength.  When the a value of the fiber is at the optimal position, the bandwidth exceeds 13 GHz. km. The figure also reflects that the bandwidth of a multimode fiber cable is very sensitive to the A value. To achieve the maximum bandwidth, A value (core refractive index) needs to be very finely controlled, otherwise various defects in the core profile during the manufacturing process will affect the actual bandwidth of the multimode fiber optic cable.

With the advancement of optical fiber cable design and manufacturing technology, the bandwidth of multimode optical fiber cable has been greatly improved. Table 1 shows different types of standard multi-mode fiber cables. The 62.5 µm multimode fiber optic cable has a higher numerical aperture and a larger core, which can couple the light-emitting diode light source (LED) into the fiber, and supports 2 km at a rate of 10 Mbit/s or even 100 Mbit/s. data transmission. With the development of Ethernet standards and low-cost 850 nm VCSELs, multimode fiber cables with a core diameter of 50µm are more popular in the market. The fiber has lower modal dispersion and higher bandwidth, and the spot size and numerical aperture of the VCSEL is smaller than that of the LED, and the laser can be easily coupled into the 50 µm fiber. By optimizing the fiber manufacturing process and adopting advanced refractive index control technology, the 50 µm multimode fiber cable has developed from OM2 (500 MHz. km) to OM3 (2 000 MHz. km), and now it has developed to OM4 (4 700 MHz. km). ).

For the multimode fiber system using 850 nm VCSEL, further increasing the bandwidth of the OM4 multimode fiber optic cable will not enable the optical module to transmit longer distances, because the system bandwidth depends on the effective mode bandwidth and dispersion of the fiber optic cables (related to the line width of the VCSEL laser and the fiber wavelength). If the system bandwidth needs to be increased, in addition to the effective mode bandwidth of the optical fiber cable, the dispersion value needs to be optimized. Partial dispersion can be compensated by differential mode delay (DMD) multimode fiber optic cable, or 850 nm VCSEL with a narrower line width or working in the long-wave region with lower dispersion

What is an Ethernet Switch Used For?

by http://www.fiber-mart.com

A industrial Ethernet switch is a device that apply to expands the network. It can provide more connection ports in the sub-network to connect more computers. It is generally used for LAN-WAN connections. With the development of the communications industry and the advancement of the informationization of the national economy, the network switch market has steadily increased. It has the characteristics of high performance-price ratio, high flexibility, relatively simple, and easy to implement. Therefore, Ethernet technology has become the most important LAN networking technology today. And industrial Ethernet switches have become the most popular switches. 

1. Industrial switches can be connected to the same type of network.

When the scale of the network expands, it becomes impractical to simply extend the network cable. And for different LANs, to realize data transmission between each other and share network resources, special connection equipment is required to realize network expansion. The Industrial Ethernet switch which is connected to the same type of network realized network expansion. At the same time, the development of the network sites, geographical range and business volume have promoted the rapid development of network interconnection. 

2. Industrial Ethernet switch can be interconnected different types of networks

In addition to being able to connect the same type of network, the Industrial Ethernet switch can also play an interconnection role between different types of networks (such as Ethernet and Fast Ethernet). Nowadays, many Industrial Ethernet switches can provide high-speed connection ports that support Fast Ethernet or FDDI, etc., which are used to connect to other network switches in the network or provide additional bandwidth for key servers that take up large bandwidth.3. Industrial Ethernet switch can provide fast network service

Sometimes in order to provide faster access speed, we can connect some important network computers to the switch ports directly. In this way, key servers and important users of the network can get faster access speeds and support greater information flow.

The main functions of the Industrial Ethernet switch include physical addressing, network topology, error checking, frame sequence and flow control. At present, the Industrial Ethernet switches also have some new functions, such as support for VLAN (virtual local area network), support for link aggregation, and some even have the function of firewall. 

The introduction of Juniper switch models

by http://www.fiber-mart.com

JuniperNetworks is a network communications equipment company,it was founded in February 1996.Headquartered in California, with offices in 47 countries, more than 9000 employees.Customers include the service providers in world’s top 130 , 96 companies in Fortune 100 and hundreds of public sector organizations. Mainly supplies IP network and information security solutions.

The main product line of Juniper includes WAN Acceleration,VF series,E series, J series, M series, T series Router products,SRX series firewall, EX series network switch and SDX service deployment systems etc.

Juniper Switches divide into EX series Ethernet switches and QFX series switches.

The product lines of EX series Ethernet switches: EX2200, EX2500, EX3200, EX3300, EX4200, EX4300, EX4500, EX4600, EX6200, EX8200 and EX9200.

The product lines of QFX series switches: QFX5100, QFX5200 and QFX10000.

With the continuous development of optical fiber communication products, customers pay more attention to the compatibility of optical transceiver. ETU-Link Technology Co ., LTD as a professional manufacturer of optical transceiver, we have the specialized switch to test the product to check whether the products work normally and audit the eeprom information.

The following is a brief introduction about the Juniper QFX series Switches.

QFX5100 Switch:

QFX5100 switch is a low-latency and high-performance 10GbE/40GbE switch,it can be used as flexible building blocks for multiple data center array architectures.

5 kinds available QFX5100 switch models:QFX5100-48S,QFX5100-48T,QFX5100-24Q,QFX5100-24Q-AA and QFX5100-96S.

QFX5200 Ethernet switch:

QFX5200 Ethernet switches offer flexible connection options(from 10GbE to 100GbE), is the ideal choice for the next generation IP data center deployment.

Two versions of QFX5200 can be used:QFX5200-32C is a compact 1 U platform that provides 32 QSFP+/QSFP28 ports;QFX5200-64Q is a 2 U switch that provides 64 QSFP+ or 32 QSFP28 ports.

QFX10000 Switch:

QFX10000 switches are highly scalable, high-density platforms,supports multiple 10GbE/40GbE/100GbE deployment,provides a reliable basis for the most demanding data centers.The design of QFX10000 switch can adapt to the future of the Chipset upgrade,with a throughput up to 200 Tbps,support 400GbE interface(Future availability).

QFX10000 series contains 4 models,provides a flexible solution for each data center application:QFX10002-72Q,QFX10002-36Q,QFX10008 and QFX10016.

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