How much can the theoretical maximum loss of optical fiber exceed? It depends on what type of optical fiber you use and what it is used for. Even if the loss of the optical fiber is large, and the luminous power of the equipment interconnected by the optical fiber is large, the optical power received after transmission through the optical fiber can still be communicated within the receiving range.

In use, the optical fibers that were originally interconnected through LH/LX GBIC had too much attenuation after several failures and remelting, so they had to be replaced with ZX GBIC. After all, the cost of redrawing the cable is much higher than buying a GBIC.

Take GBIC as an example (now SFP is used more), you can use the fiber attenuation as long as it is within the following receiving range, of course, you have to consider the luminous power: the reference receiving range of multimode SX is: 0 ~ -17 The reference receiving range of dBmLX/LH is: -3 ~ -19 dBm The reference receiving range of ZX is: -3 ~ -23 dBm The loss of the optical cable is generally in the fusion splicing and joint parts, and the connection loss is ≤0.08dB as required, and the construction personnel are generally average. are relatively low and difficult to achieve. The insertion loss of the connector is less than 0.5dB, and the attenuation of the optical cable itself is less than 0.2dB/km. According to practical experience, the construction quality of optical cable is difficult to achieve. Optical cable construction is a high-tech job, but it is done as a physical job in China.