Where to buy Submit Orders
Home / Resources / Blog & News

Fiber Attenuation Guide: How to Minimize Signal Loss in Your Network



Fiber attenuation refers to the loss of optical power in the optical fiber transmission process. This blog will analyze what causes attenuation in optical fiber, types of attenuation in optical fiber communication, and optimizations on how to minimize the signal loss in your network.

Intro: fiber attenuation issue is essential for fiber optic system

Optical fiber communication is becoming increasingly popular with the growing development of information technology. The optical fiber communication system uses optical fiber as the transmission medium and optical wave as the transmission carrier. With the advantages of large capacity, long distance, and high stability, optical fiber communication is widely applied in various fields. However, signal loss is inevitable in any fiber-optic system. For large-area optical fiber laying, it is necessary to consider the poor communication and signal interruption caused by signal loss. Don’t worry, there are ways to minimize fiber attenuation and keep your network running smoothly. This article will discuss the different types of attenuation in optical fiber communication, the main reasons for the attenuation in fiber optics, and how to prevent them. We'll also provide a few tips on troubleshooting signal loss issues. So don't miss out - read on to learn more!

What causes attenuation in fiber optics

In the process of fiber optic signal transmission, the transmission quality will generally be affected by fiber optic attenuation and dispersion. Fiber attenuation defines the loss of optical power in the optical fiber transmission process. Fiber optic cable is made of glass or plastic fiber. Those fiber material determines the longer the fiber cable length, the greater the optical power loss. The fiber attenuation determines the maximum distance allowed between the optical transmitter and the receiver without the help of signal amplification. 


There are many types of attenuation in optical fiber communication, including absorption loss, scattering loss, bending loss, etc. Understanding the causes of optical fiber attenuation is the premise for further research on reasonable measures to reduce signal loss. Then, the article next will analyze what causes attenuation in optical fiber:

Factor 1: material

The main types of materials used for optical fibers are glass and plastic, which will absorb optical signals to varying degrees. This absorption loss leads to the attenuation of optical fiber. On the other hand, the impurities are due to the impure material or incomplete fiber manufacturing process. On the other hand,  impurity due to the imperfect fiber manufacturing process is also the major reason leading to fiber optic cable attenuation. For this reason, the impurity loss can be reduced by optimizing the manufacturing process.

Factor 2: optical fiber scattering

Optical fiber scattering due to the randomly-distributed internal structure of the fiber is also a major factor that affects the quality of transmission. Since the scattering changes the direction of the optical signals transmitted in the fiber, the optical power transmitted is naturally reduced. The following figure describes one of the major types of optical fiber scattering, Rayleigh scattering, which will cause some light waves to scatter back to their origin.


Rayleigh Scattering
Rayleigh Scattering

Factor 3: fiber bending

In the fiber implementation process, it is unavoidable that the optical cable will bend according to the laying environment. The attenuation caused by fiber bending mainly occurs in the bending area, where the optical signal cannot be totally reflected, so some optical signals will get loss. 

Factor 4: fiber loss spectra

Fiber attenuation varies in different wavelengths. The wavelength with a relatively low attenuation is called the low loss window. There are three low loss windows, 850nm, 1310nm, and 1510nm. The fiber loss spectra is shown in the following figure. With the continuous development of optical fiber manufacturing technology, it is a tendency that the fiber loss spectra will move in the low loss at a full band. The following figure shows the fiber loss spectra.


Fiber Loss Spectra

Fiber Loss Spectra

How do reduce the fiber optic attenuation?

After analyzing the causes of fiber attenuation, here comes the question, how can we properly reduce the fiber optic attenuation? Reducing the attenuation in optical fiber is very important to improve the optic fiber transmission quality and realize long-distance communication transmission. Next, this article will give a detailed analysis of the optimization measures for fiber optic attenuation.

Improve the optical fiber manufacturing and laying process

Using advanced fiber production and manufacturing technology is helpful for improving fiber purity and reducing impurities and residues. 


During the fiber laying process, to reduce the bending attenuation, it is necessary to reduce the bending radius of the optical cable and avoid unnecessary bending as much as possible. Moreover, when cutting the fiber cable in the laying process, qualified cutting equipment and professional technicians are required to avoid a large inclination angle of the cutting surface, which will lead to a bad connection and affect the transmission quality.

Optical amplification technology

Optical amplification technology refers to using optical amplifiers to amplify weak optical signals and improve optical power. The optical amplifier is mainly composed of the amplification medium and pump source. During optical amplification, the medium absorbs enough energy from the pump source and then transfers the energy to the attenuated optical signal. QSFPTEK provides fiber amplifiers (DWDM EDFA), greatly increasing optical power for long-haul WDM & OTN networks by amplifying optical signals.


DWDM EDFA Optical Amplifier

DWDM EDFA Optical Amplifier 

Dispersion compensation technology

The optical dispersion is proportional to the spectral width of optical sources. The narrow spectral source is often used for fiber optic transmission. However, with the continuous increase of information capacity, the narrow spectrum source can’t meet the growing communication demand. Therefore, dispersion compensation technology is required. 


The dispersion compensation technology reduces the overall fiber dispersion by providing the optical wave opposite to the dispersion of the optical fiber line, solving the waveform distortion caused by the fiber dispersion. QSFPTEK's Dispersion Compensation Module (DCM) uses a special fiber with negative chromatic dispersion, providing a simple and cost-effective solution for compensating dispersion, allowing signals to travel over 120km without regeneration. 


Dispersion Compensation Module

Dispersion Compensation Module



See also: How to Calculate Attenuation in Optical Fiber Cable?

Final words

Improving the stability of optical fiber transmission is the main purpose of future optical fiber communication development. This paper analyzes the main factors leading to attenuation, and also proposes optimizations. We hope it will be helpful for minimizing signal loss in your network. If you are still confused about fiber optic cable attenuation, our professional tech support is standing by. QSFPTEK also provides multiple high-performing fiber optic cable types in full compliance with all applicable certifications and regulations, welcome to consult via sales@qsfptek.com.



Contact us