1) Optical fiber manufacturing
Fiber manufacturing methods are mainly: in-tube CVD (chemical vapor deposition) method, in-stick CVD method, PCVD (plasma chemical vapor deposition) method and VAD (axial vapor deposition) method.
2) Attenuation of optical fiber
The main factors causing fiber attenuation are: intrinsic, bending, extrusion, impurities, inhomogeneity and docking, etc.
Intrinsic: is the inherent loss of the fiber, including: Rayleigh scattering, inherent absorption, etc..
Bending: the optical fiber bending part of the light in the fiber will be lost due to scattering, resulting in loss.
Extrusion: the loss caused by the tiny bend in the fiber when it is squeezed.
Impurities: impurities within the fiber absorb and scatter the light propagating in the fiber, resulting in loss.
Non-uniform: loss caused by the non-uniform refractive index of the fiber material.
Butt splice: loss caused by fiber butt splice, such as: different axis (single-mode fiber coaxiality requirements less than 0.8μm), end face and axis is not perpendicular, end face is not flat, butt core diameter mismatch and poor fusion quality, etc.
