Fiber optic attenuation is the phenomenon of energy loss of optical signals during fiber optic transmission. The following are some of the main causes of fiber optic attenuation:
1. Absorption Loss: The energy of the optical signal in the fiber optic material is absorbed by the material and converted into thermal energy, resulting in weakened signal strength. Absorption attenuation is mainly caused by the intrinsic absorption of fiber optic materials and impurity absorption, where the intrinsic absorption is the fiber optic material itself for a specific wavelength of light absorption, and impurity absorption is due to impurities or impurities introduced by the impurities and the interaction of light and the absorption caused by the impurities.
2. Scattering Loss: Scattering attenuation is the loss of energy due to the scattering of optical signals in optical fibers. The main scattering mechanisms in optical fibers include Rayleigh scattering, Mie scattering and Bragg scattering.Rayleigh scattering is the most important scattering mechanism in optical fibers, it is due to small inhomogeneities in the fiber caused by the optical signal propagation along the fiber in the process of energy scattering.
3. Bend Loss: When an optical fiber is bent, the optical signal will be attenuated due to the change in refractive index produced by the bending. The degree of bend attenuation depends on the radius of curvature of the fiber and the refractive index distribution of the fiber. A smaller bend radius and a larger refractive index distribution difference will result in a larger bend attenuation.
4. Dispersion Loss: Dispersion attenuation is the loss of energy due to the propagation speed of optical signals in optical fibers with respect to the wavelength. Dispersion in the fiber will lead to diffusion of light signals of different wavelengths in the transmission process, resulting in signal attenuation and distortion.
5. End-face Reflection Loss: When the optical signal is reflected back from the end face of a fiber optic connector interface or connection point, end-face reflection attenuation occurs. The degree of end-face reflection attenuation depends on the quality of the connector design and manufacture, as well as the alignment accuracy between the connectors.
6. Leakage Loss: Loss attenuation is the energy loss caused by the optical signal leaking out of the fiber. Leakage attenuation is usually caused by inconsistencies in the geometric parameters of the fiber, fiber damage, or poor fiber connections.
These factors or a combination of them can lead to fiber attenuation. In order to reduce attenuation, proper fiber design and manufacturing processes, selection of low attenuation fiber materials, optimization of connector and connection technologies, and ensuring fiber quality and maintenance are required.
