Benefits of Using Fiber Optic Attenuators with Doped Fiber

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

Fiber optic attenuators are used in networking applications where an optical signal is too strong and needs to be reduced. There are many applications where this arises, such as needing to equalize the channel strength in a multi-wavelength system or reducing the signal level to meet the input specifications of an optical receiver. In both scenarios, reducing the optical signal strength is necessary or else system performance issues may arise.
Types of Fiber Optic Attenuators
There are many forms which can be taken by optical attenuators, but the two basic types of fiber optic attenuators are fixed and variable. In this article, we will focus on the fixed type.
The size of the build out attenuator is approximately 1.25 inch. Many have a male interface connector at one end and a female interface connector at the other end but female to female interface connectors are also available. The fabrication of the build-out style is typically accomplished using with air gap attenuation or doped fiber attenuation.
What are Air Gap Attenuators?
Air gap attenuators accomplish the loss of optical power with the help of two fibers that are separated by air to yield the loss. These attenuators can be fixed or variable, but a downside is that they can be vulnerable to dust contamination and are also vulnerable to changing temperatures and moisture. One must also be cautious where they are used. For example, multi-channel analog systems, like ones used by CATV, this attenuator can create second order distortions that reduce the performance of the system.
What are doped Fiber Attenuators?
As the name suggests, doped fiber attenuators consist of a small fiber piece along with metal ion doping which provides the exact attenuation and interfaces in between female and male connections on the attenuators. These types can be wavelength sensitive because of their fabrication. The primary reasons why these doped fiber attenuators are preferred include:
Not susceptible to dirt, moisture, or temperature variations
Provide a stable performance over wide wavelength variations and band passes.
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Benefits of Using Fiber Optic Attenuators with Doped Fiber

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

Fiber optic attenuators are used in networking applications where an optical signal is too strong and needs to be reduced. There are many applications where this arises, such as needing to equalize the channel strength in a multi-wavelength system or reducing the signal level to meet the input specifications of an optical receiver. In both scenarios, reducing the optical signal strength is necessary or else system performance issues may arise.
Types of Fiber Optic Attenuators
There are many forms which can be taken by optical attenuators, but the two basic types of fiber optic attenuators are fixed and
variable. In this article, we will focus on the fixed type.
Fixed Attenuators
The further classification of fixed attenuators is
Build – out style
In-line patch cord
The size of the build out attenuator is approximately 1.25 inch. Many have a male interface connector at one end and a female interface connector at the other end but female to female interface connectors are also available. The fabrication of the build-out style is typically accomplished using with air gap attenuation or doped fiber attenuation.
What are Air Gap Attenuators?
Air gap attenuators accomplish the loss of optical power with the help of two fibers that are separated by air to yield the loss.
These attenuators can be fixed or variable, but a downside is that they can be vulnerable to dust contamination and are also vulnerable to changing temperatures and moisture. One must also be cautious where they are used. For example, multi-channel analog systems, like ones used by CATV, this attenuator can create second order distortions that reduce the performance of the system.
What are doped Fiber Attenuators?
As the name suggests, doped fiber attenuators consist of a small fiber piece along with metal ion doping which provides the exact attenuation and interfaces in between female and male connections on the attenuators. These types can be wavelength sensitive because of their fabrication. The primary reasons why these doped fiber attenuators are preferred include:
Not susceptible to dirt, moisture, or temperature variations
Provide a stable performance over wide wavelength variations and band passes.
M2 Optics has been an established manufacturer and innovator of professional optical fiber platforms for fiber network simulation, latency / optical time delay, training, and demonstration applications. Our customer base includes many of the world’s most
recognized communications service providers, equipment manufacturers, data centers, web service providers, financial institutions, research institutions, and government agencies.

What Fiber Attenuator Do You Use? LC Attenuator or SC?

Fiber optic attenuator is an essential passive component in the optical communication system. With the advancement of DWDM technology, as well as the potential to flexibly upgrade the reconfigurable optical add-drop multiplexer (ROADM), the demand for optical attenuator is sure to soar, especially for optical variable attenuator.

 

Types of Fiber Optic Attenuators

 

Optical attenuator takes a number of different forms. They are typically grouped as fixed optical attenuator and optical variable attenuator.

 

Fixed Optical Attenuator

Fixed attenuator, as the name of which has indicated clearly, is designed to have an unchanging level of attenuation, expressed in dB, such as 1dB, 5dB, 10dB, etc. Fixed value attenuators consist of in-line type and connector type. In-line type looks like a plain fiber patch cable. It has a fiber cable terminated with two connectors which you can specify types. Connector type attenuator looks like a bulk head fiber connector, with a male connector interface on one end and a female interface connector on the opposite end. It mates to regular connectors of the same type such as FC, ST, SC and LC. Their applications include telecommunication networks, optical fiber test facility, Local Area Network (LAN) and CATV systems.

Optical Variable Attenuator

Optical variable attenuator, or variable optical attenuator, generally uses a variable neutral density filter. It has advantages of being stable, wavelength insensitive, mode insensitive, and offering a large dynamic range. Variable optical attenuator is generally used for testing and measurement, but it is also widely adopted in EDFAs (Erbium-Doped Fiber Amplifier) for equalizing the light power among different channels. Basically, there are two types of optical variable attenuator: stepwise variable attenuator and continuously variable attenuator. Stepwise variable attenuator can change the attenuation of the signal in known steps such as 0.1 dB, 0.5 dB or 1 dB. Continuously variable optical attenuator produces precise level of attenuation with flexible adjustment. Thus, operators are able to adjust the attenuator to accommodate the changes required quickly and precisely without any interruption to the circuit.

 

How to Use Fixed Fiber Attenuator?

 

As shown in the figure below, fixed fiber optic attenuators should be always installed at the receiver end of the link (X in the drawing). This is because it’s more convenient to test the receiver power before and after attenuation or while adjusting it with your power meter at the receiver, plus any reflectance will be attenuated on its path back to the source.

For female to male fixed fiber optic attenuators, we can plug the patch cord to the female fiber optic adapter of the attenuator. And then plug the male plug connector of the attenuator to the equipment directly. For female to female fixed fiber optic attenuators, we should plug the two patch cords to the two female fiber optic adapter of the attenuator (shown in the figure below).

 

Conclusion

Fiber optic attenuator is a passive device used to reduce the power level of an optical signal because too much light can overload a fiber optic receiver and degrade the bit error ratio (BER). To achieve the best BER, the light power must be reduced by using fiber optic attenuator. Fiber-MART provides optical attenuators with various connector types, such as FC/SC/ST/LC/E2000, available with APC or UPC polish. Any question pls feel free to contact me at service@fiber-mart.com

Introduction of Fiber Optic Attenuators

Do you know what is the fiber attenuator used for? As we know, the source of the single mode fiber is laser, the power of which is extremely strong. Therefore we can use single mode fiber to achieve long distance transmission. But, if the transmission distance over single mode fiber is too short, too much light may overload a fiber optic receiver, which may cause serious high bit error rates. How to solve this? Fiber attenuator should be inserted at the receiver end to reduce the power to the proper level. This article sheds light on types, and applications of optical attenuators, helping you to choose a right one.

What is Fiber Attenuator?
Fiber optic attenuator is a passive device used to reduce the power level of an optical signal because too much light can overload a fiber optic receiver and degrade the bit error ratio (BER). To achieve the best BER, the light power must be reduced by using fiber optic attenuator. Generally, the optical attenuators are used in single-mode long-haul applications to prevent optical overload at the receiver.

Optical attenuator reduces signal power by absorbing the light, like sunglasses absorb the extra light energy. Or by scattering the light like an air gap. Fiber optic attenuators are commonly used in two scenarios:

1.Attenuators are permanently installed in a fiber optic links to properly match signal levels at transmitter and receiver.
2.In fiber optic power level testing. Attenuators are used to temporarily add a calibrated amount of signal loss in order to test the power level margins in a fiber optic system.

Types of Fiber Optic Attenuators

Optical attenuator takes a number of different forms. They are typically grouped as fixed optical attenuator and optical variable attenuator.

fixd

What is Fixed Fiber Attenuator?
Fixed fiber optic attenuator, also called fixed plug type or fixed build-out fiber attenuator, is used in fiber optic communications to reduce the optical fiber power by a certain level. Typical attenuation values are between 1 and 30 dB. Usually, it has a male plug connector at one side to allow fiber attenuator to be plugged directly into receiver equipment or adapters in patch panel, and has female type fiber optic adapter at the other side to allow the patch cords to plug in. Fixed fiber optic attenuator name is based on the connector type and the attenuation level. LC attenuator 5dB means this attenuator uses LC fiber optic connector, and it can reduce the optical fiber power level by 5dB.

What is optical variable attenuator?
Optical variable attenuator can also be made as a plug-in card. It is a part of Fiber-Mart, all-in-one multi-service transport system. This hot-swappable plug-in variable optical attenuator is an online attenuation adjustment device, only occupying one slot in the 1U/2U/4U chassis. It is applied to applications that optical power required strict control, such as to balance signal strengths in a DWDM network system. Card optical variable attenuator adopts MEMS technology and could continually and variably reduce the light intensity in the optical network and help simulate distance or actual attenuation in the fiber optic testing work. With the card design, this optical variable attenuator is easy to install and remove without any tool. The online attenuation adjustment also contributes to safer business.

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How to use Fiber Optic Attenuators in data link?

For a single-mode applications, especially analog CATV systems, the most important parameter, after the correct loss value, is return loss or reflectance. Many types of attenuators (especially gap loss types) suffer from high reflectance, so they can adversely affect transmitters just like highly reflective connectors.

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Fiber Optic Attenuator in Data Link

Choose an attenuator with good reflectance specifications, and always install the attenuator ( X in the drawing) at the receiver end of the link as shown above. This is because it’s more convenient to test the receiver power before and after attenuation or while adjusting it with your power meter at the receiver, plus any reflectance will be attenuated on its path back to the source.

Test the system power with the transmitter turned on and the optical attenuator installed at the receiver, and using an optical power meter set to the system operating wavelength. Check to see whether the power is within the specified range for the receiver.

Conclusion
Fiber optic attenuator is an essential passive component in the optical communication system. With the advancement of DWDM technology, as well as the potential to flexibly upgrade the reconfigurable optical add-drop multiplexer (ROADM), the demand for optical attenuator is sure to soar, especially for optical variable attenuator. The innovation in fiber optic industry never ceases, and fiber optic attenuator will evolve to have lower cost, faster response time and enhanced integration of hybrid with other optical communication devices.Fiber-Mart provides a wide range of fiber optical attenuator.Welcome to contact with us:product@fiber-mart.com.