The battery of laser pointer is optional

The battery of laser pointer is optional.
Also hope to hear from there sent to the sound. With the development of radio, electronics and automation technology, this illusion and hope has become a beautiful reality. TV phone, remote sensing technology not only brought us a vivid picture of the ends of the earth, you can hear the sound there could be heard clearly. It should be said that these achievements are inseparable from the achievements of the functional materials, information materials. With the rapid development of information science and technology, mankind has entered a new era - the information age. IT with new materials, the relationship is very close. Whether the acquisition, conversion and transmission of information, or information processing, storage and display, each link can not be separated from the new materials.
Maximum capacity of copper cable communication system can only be simultaneous transmission of 13 circuit television, a new communications network requires simultaneous transmission of tens of thousands of road or even hundreds of thousands of road. How to do it the new way of  optical fiber made of fiber optic cable instead of copper cable to solve this problem. Optical fiber communication has many features. The first characteristic is its large capacity. A 13mm thick cable, containing 144 fibers through 48384 Tel compared with coaxial cable, and increases the capacity of thousands of times. The second characteristic is resistant to electromagnetic interference, free from the influence of lightning performance of confidentiality or The third characteristic is rich in raw materials, low cost. Optical fiber using the most abundant on Earth silica is sand made of. The color is one of the biggest different points of these two kinds of laser pointer .
Take the United States in New York City to Boston, a 600km long fiber optic cable communication lines, the maximum communication capacity is 80000 Tel savings to invest $ 50 million than the construction of the same size coaxial cable system. At present, the main research topics of the optical fiber is to try to further reduce the optical loss, an increase of the distance between the relay station. From the optical fiber applications, since the optical fiber communication, optical loss lower then 20dB per km per kilometer 1dB look. People are to enter to the loss of 0.1dB per km. Once you achieve this goal, the distance between the relay station can be extended to 100km. In order to further reduce costs. Lead to market high-end imported materials prices artificially high to the phenomenon of profiteering. Research and development of the project, and realize industrialization related to national security, the industry can develop high-end, whether the possession of the initiative and other key issues in the new round of industrial revolution in China. This team is market-oriented material of high reliability and excellent process performance through the design of special molecular structure and precision with each component.