Fiber optic cable is a communications cable consisting of two or more glass or plastic optical fiber cores located within a protective cladding and covered by a plastic PVC outer sleeve.
Signal transmission along internal optical fibers generally uses infrared light.
What are the factors causing fiber attenuation in optical fiber cables? Factors causing fiber attenuation include scattering loss, absorption loss and micro-bending loss.
Scattering loss is mainly caused by Rayleigh scattering, which is caused by microscopic refractive index fluctuations caused by the irregular molecular structure of glass. It is the inherent loss of optical fiber and is also the minimum limit of optical fiber attenuation.
It is inversely proportional to λ4.
When the wavelength is less than 0.8 microns, Rayleigh scattering loss rises rapidly, limiting the use of optical fibers.
The intrinsic absorption loss of the optical fiber matrix material SiO2 and the doped oxide molecules causes the attenuation of the optical fiber to increase rapidly when the wavelength is greater than 1.7 microns.
Therefore, the wavelength used by this type of optical fiber is limited to the range of 0.8 to 1.7 microns.
In this range, the attenuation is mainly caused by the transition metal ions and OH- contained in the impurities Fe++, Cu++ and OH- in the quartz glass.
Caused by absorption loss.
With the improvement of the purification process, the impurity absorption loss has been basically eliminated, thus reaching the limit of Rayleigh scattering loss.
Irregular micro-bending of optical fibers causes mode coupling and micro-bending losses. Therefore, micro-bending of optical fibers should be avoided as much as possible during processing and use.
