1. This sign: is the inherent loss of optical fiber, including: Ruili scattering, inherent absorption, etc.

2. Bending: When the optical fiber is bent, some optical in the fiber will lose due to scattering, causing losses.

3. Squeezing: Losses caused by tiny bending when the fiber is squeezed.

4. Increases: The light that is absorbed and scattered in the optical fiber in the fiber, causing losses.

5, unevenness: loss caused by uneven refractive index of optical fiber materials.

6. Docking: Losses generated during optical fiber docking, such as: different axes (monocular fiber -fiber coaxiality requirements are less than 0.8 μm), the end surface is not vertical and the axis heart, the end surface is uneven, the docking heart diameter is not matched and the melting quality is poor.

7. Multi -mode optical fiber: Central glass core teaching (50 or 62.5 μm), which can pass the light of various modes. However, the color scattered between its models is large, which limits the frequency of transmitting digital signals, and the increase will be more serious. For example, the optical fiber of 600MB/KM is only 300MB bandwidth at 2km. Therefore, the distance between the multi -mode fiber transmission is relatively close, generally only a few kilometers.

8. Single -mode optical fiber: Central glass core teaching (the core diameter is generally 9 or 10 μm), and only one mode of light can be passed. Therefore, the color of the model is very small and suitable for remote communication, but its color color disperse has a main role. In this way, the single -mode fiber has high requirements for the width and stability of the light source, that is, the width of the spectrum is narrow, the stability is better, and the stability is better. Essence

9. Conventional optical fiber: The optical fiber production chief has the optimization frequency of fiber transmission on a single wave of light, such as 1300 μm.

10. Color -scattered displacement optical fiber: The optical fiber production chief will optimize the frequency of optical fiber transmission on the light of two wavelengths, such as: 1300 μm and 1550 μm.

11. mutant optical fiber: The refractive index from the optical fiber center core to the glass bag is mutated. The cost is low, and the color of the mold is scattered. Suitable for short -distance low -speed communication, such as: industrial control. However, because the single -mode optical fiber is small, the single -mode fiber uses a mutant type.

12. Gradient fiber: The refractive index of the optical fiber center core to the glass pack layer is gradually becoming smaller, which can spread the high mold light according to sine. Most of the multi -mode fiber is gradient fiber.

13. Electric transmitter: The main task is multi -way reuse of PCM encoding and signals.

Multi -road reuse refers to transmission combining multi -way signals on a physical channel, and separate signals by special devices to the receiving end. Multi -way reuse can greatly improve the utilization rate of communication lines.

In the optical fiber communication system, the binary light pulse "0" and "1" code transmitted in the fiber of fiber, which is generated by binary digital signals on the light source. The digital signal is produced, quantified, and encoded for continuous changing simulation signals. It is called PCM (Pulsecode Modulation), that is, pulse coding modulation. The digital signal of this electricity is called a digital baseband signal, which is generated by the PCM electrode.