The main factors causing the attenuation of optical fibers are intrinsic, bending, extrusion, impurities, inhomogeneity and docking.
Intrinsic loss of optical fibers, including Rayleigh scattering, intrinsic absorption, etc.
Bending: When the optical fibers are bent, part of the light in the optical fibers will be lost due to scattering, resulting in loss.
Extrusion: The loss caused by a slight bending of an optical fiber when it is extruded.
Impurities: Impurities in optical fibers absorb and scatter light propagating in the fibers, resulting in losses.
Non-uniformity: Loss caused by non-uniform refractive index of optical fiber materials.
Docking: The loss caused by fiber docking, such as: different axes (coaxiality of single-mode fiber is less than 0.8 um), end face is not perpendicular to the axis, end face is uneven, docking center diameter is not matched and welding quality is poor.
When light is emitted from one end of the optical fiber and from the other end, the intensity of light decreases. This means that the energy of light decreases a part after the light signal propagates through the optical fiber. This indicates that there are some substances in the optical fibers or for some reason, which block the light signal. This is the transmission loss of optical fibers. Only by reducing the loss of optical fibers can the optical signal be unimpeded.