Can you explain the principle that allows fiber optic cables to transmit signals?

Fiber optic cables containing silica called filamentous crystal crystalline silica is actually the main component of these filaments heap on the inner wall can be attached to the wire with the wire bent over bent when the optical signal from the wire the optical signal to one input of the specular reflection on the surface of the silica on the principle of reflective transmission until it reaches the other end of the optical signal conductor recognizer so far.

Fiber is divided into the following two categories:

1) transfer points modulo class

Transfer points modulo class of single-mode fiber and multimode fiber. Single-mode fiber core diameter is small, at a given operating wavelength only in single-mode transmission, the transmission frequency bandwidth, transmission capacity. Multimode fiber is given in the operating wavelength, can be transmitted simultaneously to a plurality of mode optical fiber. Compared with single-mode fiber, multimode fiber transmission performance is poor.

2) refractive index distribution type

Refractive index distribution type optical transitions can be divided into optical fiber and tapered optical fiber. Hopping optical fiber core refractive index and the refractive index of the protective layer is a constant. And a protective layer in the core of the interface, the refractive index changes stepwise type. Graded refractive index of optical fiber core increases as the radius decreases according to certain rules, and the protective layer of the core is reduced to the junction of the refractive index of the protective layer. Similar to the refractive index of the core changes parabola.