Dispersion in optical fibers is mainly due to the following phenomena.
1. The reason for dispersion
Chromatic dispersion is because the light in the propagation process, the wavelength of its different components of different propagation speeds caused by the phenomenon. In fiber optics, the propagation speed of red light is greater than that of blue light.
2. Normal dispersion
Normal dispersion within a single-mode fiber, long wavelength light (red light) is faster than short wavelength light (blue light), known as positive dispersion.
3. Anisotropic dispersion
The nature of the light-conducting material in the fiber determines its dispersion, but different materials may have different dispersion rates, resulting in anisotropic dispersion.
4. Dispersion compensation
The use of positive and negative dispersion of two different materials, the preparation of dual-guide optical fiber, so that the long and short wavelengths of light in the propagation of the dispersion delay offset, to achieve dispersion compensation.
5. Dispersion limits the information bandwidth
During the propagation of optical signals through optical fibers, due to the uneven dispersion of different wavelengths, the frequency components of the signal are delayed at the end of the fiber, limiting the transmission bandwidth.
6. Dispersion compensation application
Dispersion compensation technology is the key to achieve broadband fiber optic transmission, so that each single-mode fiber can achieve Tbps level of ultra-high-capacity transmission.
Therefore, in general, dispersion brings certain impact to fiber optic transmission, but can be effectively corrected by dispersion compensation technology.
