1) Optical fiber manufacturing:

At present, optical fiber manufacturing methods mainly include: in-tube CVD (chemical vapor deposition) method, in-rod CVD method, PCVD (plasma chemical vapor deposition) method and VAD (axial vapor deposition) method.

2) Optical fiber attenuation:

The main factors that cause fiber attenuation are: intrinsic, bending, extrusion, impurities, non-uniformity and docking.

Intrinsic: It is the inherent loss of the fiber, including: Rayleigh scattering, intrinsic absorption, etc.

Bending: When the fiber is bent, part of the light in the fiber will be lost due to scattering, resulting in loss.

Squeeze: The loss caused by the slight bending of the optical fiber when it is squeezed.

Impurity: The loss caused by the impurity in the fiber absorbing and scattering the light propagating in the fiber.

Uneven: The loss caused by the uneven refractive index of the fiber material.

Docking: The loss generated when the optical fiber is docked, such as: non-axial (the coaxiality of single-mode fiber is required to be less than 0.8μm), the end face is not perpendicular to the axis, the end face is not flat, the butt core diameter does not match and the welding quality is poor.