Optical fiber-principle

Optical fiber actual it is to point to by transparent material made of fiber core around it and the fiber core refractive index than a slightly lower material make it bag layer, and the light signal into fiber core, the packet layer interface, make the light signal reflected in fine in the media on core spread. General is by fiber core, the packet level and coating layer consists of the multilayer structure of symmetry cylinder medium. Optical fiber have two main characteristics: namely loss and the dispersion.

The length of each unit of optical fiber loss or attenuation (dB/km), related to the optical fiber communication system the length of the transmission distance relay station and the distance between the choice. Optical fiber dispersion reaction time delay distortion or pulse stretcher for digital signal transmission, particularly important. Each unit of length pulse (ns/km) idea, influence to a certain transmission distance and information transmission capacity.