If the Internet is compared to an information superhighway, fiber optic cable is like the cornerstone of the superhighway, so how is the high-capacity information fiber optic cable transmitted over long distances at high speed?
At the transmitting end, the information to be transmitted (such as voice) is first turned into an electrical signal, and then launched through a laser to the laser beam, the intensity of the light will change along with the frequency of the electrical signal, and launched through the fiber, at the receiving end, the detector receives the light signal and turns it into an electrical signal, which is processed to restore the original information.
Optical fiber made of glass fiber inside the optical fiber can transmit the light signal to thousands of kilometers away. Hundreds of thousands of optical fibers are combined together to make a fiber optic cable like a cable, which improves the strength of the optical fiber and greatly increases the communication capacity.
The propagation speed of light in different substances is different, so from one substance to another, the junction of the two substances will be refracted and reflected, and the angle of the refracted light will change with the angle of the incident light, when the angle of the incident light reaches or exceeds a certain angle, the refracted light will disappear and the incident light is all reflected back, which is the total reflection of light.
The optical signal is transmitted to the end point through refraction again and again in the optical fiber, the optical signal will be scattered or attenuated after refraction again and again, it is necessary to amplify the optical signal once every 50 km.
