1. Fiber marking machine fiber intrinsic loss

The intrinsic loss of optical , that is, the inherent loss of optical, is mainly due to the defect of quartz glass itself and the inclusion of metal transition impurities and OH-, which causes scattering, absorption and dispersion of light during transmission. Generally, it can divide into scattering loss and absorption loss. And dispersion loss. Among them, the scattering loss cause by the fluctuation of the atomic density in the material, the density unevenness during the condensation process, and the density unevenness cause by the density fluctuation. The absorption loss is due to the fact that the core contains metal transition impurities and OH-absorbing light, especially in the infrared and ultraviolet spectral regions. Dispersion can be classified into three categories according to the cause, namely material dispersion, waveguide dispersion, and inter-mode dispersion.

The single mode is transmitte in the fundamental mode, so there is no inter-mode dispersion. Among the intrinsic factors of single-mode, the mode diameter is the most influential to the connection loss. The connection loss due to the intrinsic factor of the single-mode is about 0.014 dB. When the mode field diameter is mismatched by 20%, a connection loss of 0.2 dB is generated [1]. The normalized frequency of multimode is V>2.404. There are multiple waveguide modes for transmission.
In addition, geometry parameters such as  core diameter, cladding outer diameter, core/cladding concentricity, out-of-roundness, optical parameters such as relative refractive index, maximum theoretical numerical aperture, etc., as long as one or more mismatches, will Produce varying degrees of intrinsic loss.

2. Fiber marking machine fiber additional loss

The additional loss of fiber-optic marking machine fibers typically consists of radiation losses and application losses. The radiation loss is cause by the  drawing process, the fiber diameter, the fluctuation of the ellipticity, the expansion and contraction of the temperature of the plastic layer and the low temperature shrinkage of the coating, which causes the microben of the  the application loss is due to the tension, bending and extrusion of the fiber. The resulting loss caused by macrobend and microbend.

The single mode fiber is transmitte in the fundamental mode, so there is no inter-mode dispersion. Among the intrinsic factors of single-mode fiber, the mode diameter is the most influential to the connection loss. The connection loss due to the intrinsic factor of the single-mode fiber is about 0.014 dB. When the mode field diameter is mismatched by 20%, a connection loss of 0.2 dB is generated . The normalized frequency of multimode fiber is V>2.404. There are multiple waveguide modes for transmission. The larger the V value, the more modes, except for material dispersion and waveguide dispersion, and inter-mode dispersion. Generally, the inter-mode dispersion dominates. The term “inter-mode dispersion” refers to the dispersion caused by the difference in group velocity when the phase constants β of the different modes of the fiber are different at the same frequency.