Silica glass fiber is mainly used as raw material, and the refractive index of fiber core and multi-component glass fiber is controlled by different doping amount. The cladding should reduce the refractive index, doped with fluorine, the core should increase the refractive index, and doped with germanium dioxide.

Multicomponent glass optical fiber, in addition to quartz, has sodium oxide, potassium oxide, calcium oxide, boron oxide and other oxides. Plastic optical fiber, its cladding and fiber core are optical fibers made of plastic. Metal coated optical fiber, coated with Ni, Cu, Al and other metal coated optical fibers. Rare earth doped optical fiber, optical fiber doped with rare earth elements such as erbium, rubidium, praseodymium, etc. Light emitting optical fiber, which is made of optical fiber containing fluorescent substances.

Light is transmitted in optical fiber by using the principle of total reflection of light. The incidence angle of the incident light and the reflection angle of the reflected light follow the refraction law. When the incidence angle increases, the reflection angle also increases. When the incidence angle increases to 90 °, all the incident light returns to the original medium. This phenomenon is the total reflection of light. Therefore, when the angle between the light incident into the fiber core and the optical axis is less than a certain value, the light will be totally reflected on the interface. At this time, the light zigzags along the zigzag path in the fiber core, but does not come out of the cladding.