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Category: Optical Amplifiers

What Is CATV EDFA and Its Advantages

What Is CATV EDFA and Its Advantages

What is EDFA?

Erbium Doped Fiber Amplifier is short for EDFA,which was applied in 90 s in the optical fiber transmission system and its popularization and application of optical fiber communication technology has brought a revolution.

EDFA is in small volume,low power consumption,easy to us.What’s more,it is convenient to install all kinds of application systems,such as SDH frame inside,CATV machine box,DWDM system frame.

The birth of Erbium Doped Fiber Amplifier is a revolutionary breakthrough.It makes possible for the long distance,large capacity,high speed optical fiber communication.The development of its research and application of optical fiber communication has important significance.In recent years,fiber optic CATV EDFA System especially 1500nm optical fiber CATV System is being rapidly develop in our country.Erbium Doped Fiber Amplifier has been widely used in optical fiber CATV system.Power amplifier allocated the optical output power of the transmitter again in the front end of the CATV system.Fiber optic trunk transmission is used for each direction.Power amplifier and power divider also can consider to reuse.From the branch of fiber backbone that far away from the front end,we can insert the Erbium Doped Fiber Amplifier to make up the branch loss.

As one of a functional modes of the Optical fiber amplifier system,there are generally two kinds of methods to insert the network management system.One is 232 c interface circuit with optical fiber amplifier to transfer parameters of the optical fiber amplifier and alarm information to the network management system,unified management,display and disposal.

Erbium Doped Fiber is the core of EDFA.It use quartz optical fiber as a substrate material,and mixed with a proportion of Er3+.When a pump into the Erbium Doped Fiber,Er3+ will be aroused to high level.Because the Er3+ on the high level is short life,it will work in the form of non – radiative transition to a higher level soon.And the population inversion is between the energy level and low level distribution.Due to the energy difference between the two energy levels is equal to 1550 nm of photon energy,it can be stimulated radiation of 1550nm light only.

Advantages of CATV EDFA

EDFA is in the low noise,has the characteristics of good gain trace,large amplifier bandwidth,compatible with wavelength division multiplexing (WDM) systems,with high efficiency,work performance is stable,mature technology and so on and so forth.It is very popular in the modern long-distance high-speed optical communication system.

◆ Good character

Before the pump generally use 980 nm,after level pump use 1480 nm.Minimizing the NF of EDFA by reasonable optimization to make the system access excellent CNR.

◆ Reliability

Use 1 u 19 “standard rack, built-in high-performance switching power supply.It can work in 85∽265 vac enterprise voltage.DC48V power supply (reservations) can be an option,too.Chassis cooling can be automatic temperature control.

◆ Intuition

This machine contains a microprocessor to monitor the working state of the pump laser, LCD displays the working parameters.

◆ Network management model:

Options type monitoring transponder to ensure to meet the national standard with the SCTE HMS standards, which can realize network management monitoring.

◆ Adjustable output optical power

Output optical power can be changed to -3dB.

◆ The power plug type:

Aluminum structure plug type switching power supply.Be good for heat dissipation and replacement.

Structure Diagram

The key technical indexes

Items EDFA
Wavelength(nM) 1545~1555
Optical input power(dBm) -5~+10
Nominal input power(dBm) +3
Noise coefficient(dB) (+3 dBm,@1550nM) 3.8~5.5
Gain Flatness(dB) <±0.3
Optical output power stability(dB) <±0.5
Polarization sensitivity(dB) <0.2
Polarization Mode Dispersion(ps) <0.5
Light fittings(IN/OUT) FC/APC
Pump work quantity(N) 1∽3
Saturation output power(dBm) 13∽25
Power supply(Vac) 115~265Power plug
Power supply(Vdc) 48Power plug
Operating temperature(℃) 0~50
Size(mm) 44×482.6×387
A competent input and output selector that you could choose

A competent input and output selector that you could choose

Advancement of technology answered many difficult queries inside a second. Multiplexer and demultiplexer (Mux Demux) may be the one that is a sophisticated creation that can help in transferring the data extremely fast. There are lots of sites that may be browsed and also the gradel quality of Mux Demux solutions is obtained that suit with all the network hardware brands. All these products are available with a good warranty and therefore are very much reliable products. An individual can mail if the product is required and then order for the same.

Mux Demux is the device that will help within the selection of most of the analog or even the signals from the digital inputs and these are then forwarded and single lines are obtained. Multiplexer will enable many signals that combine particular resource or equipment. This helps in minimizing one device per input signal to one informing line. A multiplexer that has double inputs has many select lines that will select the kind of line that holds the input pins and forward it to the pins from the output side lines. The job of the multiplexers is to make the level of data to higher amount and is passed across the network in a with time and the bandwidth.

The demultiplexer or even the double multiplexer may be the device that will absorb the one particular signaling which involves the input and can select the majority of the output lines of the data that are plugged towards the input device. The majority of the multiplexers are mainly coupled with a dumex at the conclusion to get data. The symbol that is representative of the Mux is really a two sided equal trapezoid which has the length wise side that contains the pins of input and the narrow side that contains the pins of output.

A Mux Demux will work largely by combining and separating the two optical signals which are present on different band widths that potentially double the amount capacity from the data, that is installed on the fiber plant. The only Mux terminal goes through both the bandwidths. The Demux that is of two fiber segregates particular bandwidth signal and passes onto a dedicated fiber strand and just the passive cable will allow the flow both in the directions. Both Mux and Demux are transparent to many of the networks and protocols. The reflections that are obtained by the signals are deleted by the existence of angled polished connectors that are present in the interface. Utilization of these cables will help in high segregation and occasional polar dependence.

FiberStore is definitely an China company that specialises in selling quality network connection parts. All of our multiplexer and demultiplexer possess a best warranty and incredibly competively priced as well as being of the most useful. For instance, the 100G DWDM Mux Demux can be used to provide 100G transport solution for DWDM networking system. The most popular configuration is 4, 8, 16 and 32 channels, and that we also provide 40, 44 channels. These DWDM modules passively multiplex the optical signal outputs from 4 or even more electronic devices, send them over a single optical fiber after which de-multiplex the signals into separate, distinct signals for input into electronics in the opposite end from the fiber optic link. Our standard 100G DWDM Mux/Demux package types are ABS box package, LGX package and 19 1U rackmount. We also supply custom package to meet your requirement. Here you can purchase DWDM Mux Demux modules from fiber optic products worldwide online shop with confidence.

About the author:

Fiberstore is an expert on fiber optic technologies and merchandise. Learn much more about PLC splitter and EDFA on www.fs.com.

Optical Active Devices Categories Introduction

Optical Active Devices Categories Introduction

In fiber optic networks, optical active devices are key components. It can convert electrical signals and optical signals to each other, the optical transmission system of the heart. Optical active devices are divided into the following three categories.

A. Light Source

The device that converts electrical signal into optical signal is called light source. The main light sources are light emitting diodes (LED) and laser diodes (LD).

B. Optical Detector

The device that converts optical signal into electrical signal is called optical detector. The main optical detectors are photodiode and avalanche photodiode.

The optical signal transmitted through the optical fiber reaches the receiving end, the receiving end has a light receiving element signal. But since we know of light has not yet reached the level of awareness of the electricity, so we can not direct the optical signal obtained by reducing the original signal. Between them, there are still one of the optical signals into electrical signals, and then by the electronic circuit to amplify the process, and finally restore the original signal. The reception switching element is called the light detector, or photodetector, short detector, also known as photo-detector or a photodiode. Common optical detector comprising PN photodiodes, PIN photodiodes and avalanche photodiodes (APD). Optical fiber communication systems require optical detector to be high sensitivity, fast response, low noise, stable and reliable.

C. Optical Amplifier

Optical fiber amplifier has become active devices rookie. Erbium-doped fiber amplifier (EDFA) has currently a large number of applications , while optical fiber Raman amplifier (FRA) is very promising.

Fiber amplifiers can not only amplify the optical signal directly, but also have real-time, high gain, broadband, online, low-noise, low-loss optical zoom function. They are essential key components in the new generation of fiber optic communication systems.

Since this technology not only solved the attenuation of optical network transmission speed and distance limitations, more importantly, it created a 1550nm band WDM, which can enable ultra high-speed, large-capacity, ultra-long haul wavelength division multiplexing (WDM), Dense Wavelength Division Multiplexing (DWDM), optical transmission, optical soliton transmission becomes a reality. It is epoch-making milestone in the history of optical fiber optic communication development.

In practical optical fiber amplifiers, there are mainly EDFA, semiconductor optical amplifier (SOA) and FRA, of which the EDFA amplifier with its superior performance is now widely used in long-distance , large capacity, high-speed optical fiber communication systems, access networks, optical fiber CATV networks, military systems in areas such as power amplifiers, repeater amplifiers and preamplifiers. Optical Fiber Amplifier is generally constituted of the gain medium optical fiber amplifier, the pump light input-output coupling structure.

Source: FiberStore

Why we need a Fiber Optic Amplifier

Why we need a Fiber Optic Amplifier

The fiber optic amplifier plays a significant and key role within the enhancing the capacity for a communication system to deliver information. The light signals can be transmitted by the use of optical transmitters, optical receivers and optical fiber.

The optical amplifier is a device amplifying an optical signal directly, without the need to first convert it to an electrical signal. The most popular parameter of gain from it is bandwidth and noise performance. It’s compensation for the wakening of knowledge throughout the transmission, due to fiber optic attenuation. The wavelength and also the power of the input fiber signal are decided through the fans.

Fiber optic amplifier has industry’s highest color resolution and simple amplifier, and sensor setup will lead to enhanced stability for previously difficult detection applications. What is more, it can offer you very high-output powers with diffraction-limited beam quality when utilizing it. Its saturation characteristics have the ability to prevent any intersymbol interference so that it is vital for optical fiber communications. That fiber amplifiers are often operated in the strongly saturated regime enables the highest output power. The amplified spontaneous emission will affect its gain achievable. It’s important to safeguard a high-gain amplifier from the parasitic reflections, for the parasitic laser oscillation or perhaps to fiber will be damaged by these.

Optical amplifiers could be transferred in the forward direction, in the backward direction, or bidirectional. However, its direction from the pump wave won’t modify the small-signal gain, the ability efficiency of the saturated amplifier as well as the noise characteristics. Furthermore, the amplification of a weak signal-impulse in a monocentrics nonlinear medium could be allowed because of it. Along with the advancement of we’ve got the technology, the caliber of it’s been improved greatly that it is well-liked by many companies. Besides, there are all sorts of products on the market so the people might have more opportunities to pick one that’s ideal for their needs.

However, when it comes to choice for the fiber optic amplifier, the best solution is to figure out the best providers that focus on this type of products. Because the components of this kind of products are complex, and you’re simply unfamiliar with the related details about it. The professional providers can use their professional knowledge and lots of years of experiences to provide you with wise advice, which can help you make a right decision. Of course, some providers provides you with certain warranty so that you can take it to their company for repair when it reduces.

CATV EDFA is a type of fiber optic amplifier. It is used to increase the output power of the transmitter and prolong the signal transmission distance. It’s widely requested TV signals, video, telephone, and data long haul transmission. FiberStore provides high output power and low noise EDFA CATV Amplifiers with selection of output power from 14dBm to 27dBm to meet the requirements of a high-density solution for the large-scale distribution of broadband CATV video and knowledge signals to video overlay receivers in a FTTH/FTTP or PON system.

Source: http://www.fs.com/

Erbium-doped Fiber Amplifier

Erbium-doped Fiber Amplifier

Optical amplifier is an optical communication system device. It amplifies an optical signal directly, without converting an optical signal into an electrical signal.

Erbium-doped fiber amplifier (EDFA) is the first successful optical amplifier invented by the UK Southampton University and JP Tohoku University. It is one of the greatest invention in optical communication. Erbium-doped optical fiber is incorporated a small amount of a rare earth element erbium (Er) ion. It is the core of the EDFA. From the late 1980s, the EDFA research has been making a major breakthrough continuously. As WDM technology greatly increases the capacity of optical communication, it becomes the most widely used optical amplifier device in the optical fiber communication.

Principle
EDFA is constituted by a period of erbium-doped fiber (about 10-30m) and pump light source. The stimulated emission of erbium-doped fiber under the action of the pump light source (wavelength 980nm or 1480nm), and the radiation of light varies with the change of the input optical signal, which is equivalent to the input optical signal the amplification. Studies have shown that the erbium-doped fiber amplifiers are typically 15-40dB of gain can be obtained, and the distance relay can be increased on the basis of the original more than 100km. So, why did scientists use erbium-doped fiber element to increase the intensity of light? We know that erbium is a kind of rare earth elements, and rare earth elements has its special structural features. Over the years, people have been using the method which doped rare earth elements in optical devices to improve the performance of optics, so this is not an accidental factor. In addition, why is the pump source wavelength chosen from 980nm or 1480nm? In fact, the pumping light source wavelength could be 520 nm, 650nm, 980nm and 1480nm. But the practice has proved that the 1480nm wavelength pumping light source laser efficiency is the highest, followed by the 980nm wavelength.

Advantages
The main advantage of EDFA is a high gain, wide bandwidth, high output power, high pumping efficiency, low insertion loss, and not sensitive to the polarization state.
1. Its amplifying area happens to coincide with the minimum loss area of single-mode fiber. This reduces the transmission loss of the light signal which can be transmitted relatively far distance.
2. It is transparent to digital signal format and data rate.
3. Its amplification bandwidth is so wide that dozens or even hundreds of channels can be transmitted in the same fiber.
4. It has low noise figure close to the quantum limit, which means that multiple amplifiers can be cascaded.
5. Its gain saturation recovery time is long, and has a very small crosstalk between the respective channels.

Applications
When EDFA is used in conventional optical digital communication system applications, we can save a lot of optical repeaters, and the distance relay could also be increased significantly, which is of great significance for the long-haul fiber optic cable trunking systems.

The main applications include:
1. It can be used as the light distance amplifier. Traditional electronic fiber optic repeater has many limitations. Such as a digital signal and the analog signal conversion, the repeater should be changed accordingly; repeater changes after the device is changed from a low rate to a high rate; only transmit the same wavelength of the optical signal, and the complex structure, expensive, and so on. Erbium-doped fiber amplifier to overcome these shortcomings, not only do not have to change with the change in the way of the signal, and equipment expansion or for optical wavelength division multiplexing, no need to replace.

2. It can be used for the transmitter amplifier and the optical receiver preamplifier. For the rear of the optical transmitter amplifier, the transmit power of the laser is increased from 0dB to +10 db. Optical receiver preamplifier, the sensitivity can also be greatly improved. Therefore, only the line of 1-2 erbium-doped amplifier, the signal transmission distance can be increased to 100-200km. In addition, the erbium-doped fiber amplifier problem to be solved the unique advantages of the erbium-doped fiber amplifier has been recognized by the world, and to be more widely used. However, the erbium-doped fiber amplifier there are also some limitations. For example, in the long-distance communication can not drop channel, each station business contacts is more difficult, not easy to find fault, pumping light source life is not long, as the optical fiber communication technology continues to progress, these problems will be satisfactorily resolved.