Optical fiber is short for optical fiber, which is thinner than hair. It is a tool to realize light transmission by using the principle of total reflection of light in fibers made of glass or plastic. Optical fiber was developed in the 1920s. It is made of ultra-pure timely glass at high temperature and has good light guiding ability. However, due to the great energy attenuation during transmission, it has no practical value. 1966, Dr. Charles Kao, a British Chinese, published a famous paper, proposing for the first time that glass fibers with little light transmission attenuation can be obtained by solving the problems of purity and composition of glass. 1970. Corning Glass Company of the United States first successfully drew the first timely glass fiber, and greatly reduced the energy attenuation in the fiber. In the 1990s, fluoride glass fiber with lower attenuation rate was developed. This kind of high-purity fluoride glass fiber also has strong transmission ability, and the transmission distance can reach 4,800 kilometers.