Fiber loss
To realize optical fiber communication, an important issue is to reduce the loss of optical fiber as much as possible. Fiber loss The so-called loss refers to the attenuation per unit length of the fiber, and the unit is dB/km. The level of optical fiber loss directly affects the transmission distance or the distance between repeater stations. Therefore, it is of great practical significance to understand and reduce the loss of optical fiber for optical fiber communication.
Fiber loss
Optical fiber materials contain transition metals such as iron, copper, chromium, etc., which have their own absorption peaks and absorption bands and vary with their valence states. The fiber loss caused by the absorption of transition metal ions depends on their concentration. In addition, the presence of OH- also produces absorption loss, the basic absorption peak of OH- is around 2.7 μm, and the absorption band is in the range of 0.5-1.0 μm. For pure silica fiber, the effect of loss caused by impurities can be ignored.
Solution: (1) Chemical purification of optical fiber materials, such as 99.9999999% purity. (2) Improvements in the manufacturing process, such as avoiding the use of oxyhydrogen flame heating (vapor axial deposition method)
Atomic defect absorption loss
Due to heat or strong radiation, the fiber material will be excited to produce atomic defects, resulting in light absorption and loss, but generally this effect is small.
Factors causing fiber loss
The loss factors of optical fiber mainly include absorption loss, scattering loss and other losses. These losses can be classified into intrinsic losses, manufacturing losses, and additional losses.
Fiber Loss Standard
There are many reasons that affect the transmission of optical fiber and cable, and transmission loss is one of them. It directly determines the transmission distance and stability of our optical network in our life and work. The transmission loss caused by the use of optical fiber mainly includes connection loss and non-connection loss. Then you must want to ask how much qualified fiber splicing loss is? What is the standard of optical fiber loss? Let's take a look at the details of the qualified optical fiber splicing loss and the optical fiber loss standard.
To solve the splicing loss, pay attention to the selection of high-quality optical fibers with the same characteristics. It is recommended to choose the standard optical fiber products of Finite, and strictly follow the requirements during construction, prepare a perfect optical fiber end face, and use the fusion splicer correctly to solve the non-splicing loss. Pay attention to choose the best laying method, take practical and effective protective measures and pay attention to construction requirements, etc. For different reasons, the loss should be carefully analyzed and different methods should be adopted to avoid it.
How much is the fiber splicing loss qualified? Fiber loss standard
The loss of a splice point of the optical fiber should not exceed 0.5dB, and the splice loss in general is below 0.3dB. Normal optical fibers are also lossy without a splice point. The so-called loss of optical fibers refers to the attenuation per unit length of the optical fiber, and the unit is dB/km. In the case of commonly used wavelengths of 1310nm and 1550nm, the optical loss is required to be lower than 0.3dB/km.
The transmission loss characteristics of optical fibers are one of the most important factors that determine the transmission distance, transmission stability and reliability of optical networks. There are many reasons for optical fiber transmission loss. In the construction and maintenance of optical fiber communication network, the most important concern is the cause of transmission loss caused by the use of optical fiber and how to reduce these losses.
The transmission loss caused by the use of optical fiber mainly includes splice loss (inherent loss of optical fiber, splice loss and movable joint loss) and non-splicing loss (bending loss and losses caused by other construction factors and application environment).
The splicing loss of optical fiber mainly includes: the intrinsic loss caused by the intrinsic factor of the fiber, the splice loss and the movable joint loss caused by the extrinsic factor.
The inherent loss of fiber is mainly due to the inconsistency of the fiber mode field diameter; the mismatch of the fiber core diameter; the non-circular core section; the poor concentricity between the core and the cladding. The splice loss of the splice loss extrinsic factor is mainly caused by the axial dislocation; the axis (folding angle) is inclined; the end face is separated (gap); the fiber end face is incomplete; the refractive index difference; It is caused by other factors such as the cleanliness of the electrodes of the welding machine, the setting of welding parameters, and the cleanliness of the working environment.
