Principle of optical fiber communication is first necessary to transfer in the sender information (such as voice) into electrical signals, and then modulated onto the laser beam emitted from the laser, so that the intensity of light with the electric signal amplitude (frequency) changes, and sent through an optical fiber; at the receiving end, the detector receives the optical signal converts it into an electric signal, after demodulation to restore the original information.

According to the Ministry statistics, from January to June this year, the national new 1.386 million kilometers of optical cable, optical cable line total length of 18.838 million kilometers, an increase of 18.1%, 4G network to promote the rapid development of optical fiber and cable industry.