When it comes to lasers, people are no strangers to it. There should be many kinds of applications of lasers in life, such as laser pointer correction of myopia, laser beauty, etc. In addition to medical applications, lasers are also used in industrial, scientific research, information and military fields. If you want to know more about the application of laser pointer in environmental detection and national defense, let Dr. Hua Dengxin from the Lidar Atmospheric Remote Sensing Research Center of Xi'an University of Technology tell you.
What is a laser. Laser is a kind of special light that uses external energy such as light energy, heat energy, electric energy, chemical energy or nuclear energy to excite matter to generate stimulated radiation. Laser light is stimulated radiation of light. Compared with ordinary light sources, the characteristics of lasers are obvious, with good directivity (small divergence angle). The searchlight illuminates the moon. The seemingly parallel searchlight has a spot diameter of 10 meters when it is 1 km. When the laser illuminates the moon, the spot diameter is about 2 kilometers. High brightness, good monochromaticity (pure color), good coherence, light speed propagation (3 × 108m / s) are all characteristics of laser.
The phenomenon of light in nature is ubiquitous, and people's understanding of light has undergone a complex evolutionary process, which is still not over yet. In particular, the appearance of green laser pointer changed people's perception of light. In 1960, American physicist Mayman developed the first ruby laser, which brought a revolution to optics and greatly promoted the development of optics and related sciences.
The development of laser technology. As a carrier of modern information transmission, light has played a great role in modern science. The Nobel Prize in Physics also affirms the modern development of optics. From the laser cooling in 1997, the semiconductor laser in 2000, the quantum optical precision measurement technology in 2005, and the optical fiber communication CCD in 2009. The great social changes brought about by the advancement of laser technology have been recognized by society and people.
In 2009, the Chinese expert Gao Kun won the Nobel Prize in Physics. Since 1957, he has been engaged in the research of the application of optical fibers in the field of communications. In 1966, he published a paper entitled "Optical Frequency Dielectric Fiber Surface Waveguide" The basic principle of the application of optical fiber in communication is proposed. The first fiber optic system was launched in 1981. Since then, the use of optical fibers made of quartz glass has become more and more widely used, and a revolution in optical fiber communication has been launched worldwide.
Since then, the optical fiber, which is thinner than human hair, has replaced the huge millions of copper wires and become an information transmission channel with a huge transmission capacity, which has completely changed the communication mode of human beings. Optical fiber as the carrier of light and sensor device, the development and application of its technology all depend on the advancement of red laser pointer technology. With the development of optics, especially the advancement of laser and optoelectronic technology, people's understanding and application of light have also been deepened. Optics has penetrated into various social fields such as medicine, geology, aerospace, military, entertainment and so on.