Laser and fiber are twin brothers. The peak power of the laser is very large, which can reach hundreds of thousands of megawatts. Due to its large energy, it can be used for laser cutting, laser medical treatment, and laser weapons. In addition, laser applications include laser ranging, laser gyro, and laser processing. The simplest application of laser medicine is filling teeth. Every patient is reluctant to listen to the sound when grinding teeth. However, if you use a laser pointer to fill your teeth, you can use a laser to cut off the surface of the tartar and part of the insect teeth. There is no sound. For laser processing, you need to make a gear on a part with thick hair. The hair is only 50 microns. To make a flat gear on this, general mechanical means are not available, and only laser can be used.
Fiber and laser have changed people's lives. Every Internet access is transmitted by fiber, so we can now connect with various parts of the world. Optical fiber as a carrier of light, its application development depends on the laser. What is hidden in the optical fiber is not current, but light. This light is the green laser pointer. The current optical fiber communication and optical fiber transmission are much faster than the previous electromagnetic wave communication, because the speed of light propagation is fast, and the speed is 300,000 kilometers per second. To give a simple example, in the early 1990s, when I called back from abroad, I could hear my echo in the microphone, but as long as the mobile phone is in hand, it is very clear to reach all corners of the world.
Fiber optic sensing technology can perform real-time precision detection on the deformation of large buildings such as buildings and bridges, as well as the temperature changes of large substations. How to measure the deformation of large buildings with optical fiber? In the construction process, the optical fiber is buried in the concrete, and the passage is equivalent to a blood vessel. The laser is injected through the optical fiber. Through certain sensing technology, you can know where there is a small amount of deformation, which can be detected immediately. In foreign skyscrapers, the base of the building is buried with optical fiber sensors. The optical fiber is directly poured into the cement column to monitor the deformation of the cement column in real time. This is the application of laser plus fiber.
In addition, optical cables made from multiple strands of optical fiber have spread all over the world and become the cornerstone of the Internet and global communication networks; optical fibers have also been widely used in medicine. Endoscopes such as gastroscopes can allow doctors to see the patient's body. ; Optical fiber sensing technology and systems are also widely used in industry, showing their talents in various manufacturing and mechanical processing.
The application of laser in aerospace. In the development of aerospace, the use of lasers should not be underestimated. In the lunar exploration project, Chang'e had to get a three-dimensional map of the moon before going to the moon. At this time, a laser was used to measure the distance, and a high-precision map of the lunar landform was obtained, which contributed to the next step to the moon. Yutu is going to land on the moon, there is a laser on the platform that landed on the surface of the moon.
Measure the distance between the lander and the lunar surface to land smoothly. With the rapid development of information, many need to use the network. The "Mozi" satellite launched last year is the first quantum satellite in China and the world's first. Someone will definitely ask, what is the relationship between quantum and red laser pointer? "Quantum communication refers to a new type of communication method that uses the quantum entanglement effect for information transmission. It has the characteristics of high efficiency and absolute security. However, all quantum communication networks must use laser technology."
The quantum is the smallest unit that can exhibit the characteristics of a certain substance or physical quantity. The "quantum of light" (photon) is the basic energy unit of light at a certain frequency. Compared with optical quantum communication, classic communication cannot be compared with its security and efficiency. Security-Quantum communication will never "leak", its integrated quantum encryption key is random, even if intercepted by the stolen, it can not get the correct key, so it is impossible to crack the information; Two particles with entangled states in one's hand, the quantum state of one of the particles changes, and the quantum state of the other side will change immediately. According to quantum theory, any macroscopic observation and interference will immediately change the quantum state and cause it Collapsed, so the information obtained by the stealers due to the interference has been destroyed, not the original information. Therefore, quantum communication can achieve absolutely confidential communication.