DB loss is how much of it gets lost in transit in fiber cable, the causes of DB loss include end-point contamination, bending, splicing or connector loss, etc. In fiber optics, data is transmitted via light pulses sent through thin glass strands. Although the goal is to transmit 100% of the data, there will always be some power loss or strength of signal loss, also known as DB loss. It is also called attenuation, and it is typically measured in dB. The attenuation results in a weakened signal strength. In addition, the higher the dB loss, the greater the reduction in signal power. Too much light loss leads to data loss and network failure. It signifies that the fiber cable is not up to industry standards. Therefore, it is important to minimize DB loss in fiber optic cable.
The causes of DB loss in fiber cable are various. It is caused by intrinsic fiber characteristics or operating conditions including intrinsic and extrinsic optical fiber loss. Intrinsic Optical Fiber Losses comprise intrinsic material absorption, dispersion, and scattering. Extrinsic Optical Fiber Losses contain bending, splicing, or connector loss. The total DB loss in a fiber optic link is the sum of these various loss mechanisms over the length of the cable. Generally speaking, the loss might be around 0.5 dB to 0.75 dB per kilometer for single-mode fiber optic cables. While multimode fiber optic cables, the loss might be around 2 dB to 3 dB per kilometer.
Causes of dB Loss in Fiber Cable
The causes of DB loss in fiber cable include intrinsic and extrinsic optical fiber loss.
Intrinsic Optical Fiber Losses
Intrinsic fiber optic loss occurs within the fiber optic cable core. There are several types of intrinsic losses.
Intrinsic material absorption
The material of the fiber optic core will absorb some of the optical signal as it propagates through the cable. Absorption causes dissipation of the transmitted optical power in the optical waveguide in the form of heat. Therefore, there are losses due to absorption.
Scattering
As the light travels through the fiber, it can be scattered by impurities or defects in the glass. The light is not absorbed but sent in another direction. It results in additional signal loss.
Dispersion
Dispersion refers to the distortion or spreading of an optical signal as it propagates along the fiber length. Dispersion Loss occurs when the signal’s frequency components get “smeared” due to the different speeds at which they travel through the fiber.
Extrinsic Optical Fiber Losses
Extrinsic losses in optical fiber occur due to reflections, roughness on end faces, angular errors, or radial misalignment.
End-point contamination
Fiber optic cables are made primarily of glass. The performance of fiber cabling is severely reduced when that glass is dirty. The end-point is where the fiber cable is susceptible to contamination. Touching the connector ends can severely contaminate the transmission of light by smearing the glass ends with oil and dirt. Therefore, it is important to use a scope to inspect the cable end faces to ensure a pristine surface.
Bending
When the fiber cable is bent, the light can be coupled out of the core into the cladding to increase loss. This type of damage occurs most commonly during installation.
Connectors and splices
When fibers are spliced or connected to other components, there can be additional losses due to imperfect connections. These losses cannot be completely avoided, but proper handling of fiber optic cables and high-quality fusion splicing.
Return loss
Return loss also known as reflectance, is the loss of optical power that occurs when light is reflected towards the source at an optical component’s interface.
In Conclusion
It is impossible to eliminate DB loss in fiber cable. However, fiber loss in a network can be minimized by understanding the causes of DB loss. If you want to know more about What Causes DB Loss in Fiber Cable. We’ll be happy to answer any of your questions. If you need it, please contact us: [email protected].
