Do you know lasers? Lasers have long been linked to our lives
February 26, 2020
Do you know lasers? In fact, lasers have long entered our lives. Laser is another major human development since the 20th century, following atomic energy, computers, and semiconductors. It is called the "fastest knife", "the most accurate ruler", "the brightest light" and "strange laser". ", Its brightness is about 10 billion times that of sunlight. The principle of laser was discovered by the famous physicist Einstein.
Laser and ordinary light are essentially the same, they are both electromagnetic waves, and their propagation speed is 300,000 km / s. However, the generation and emission behavior of laser light are different from ordinary light. Laser light is a non-divergent strong light generated when a substance is excited by the same energy as its molecular natural oscillation frequency. So, what is the difference between laser and ordinary light?
First, laser light is generated by excitation, while ordinary light consists of photons.
Second, the laser is directed to emit strong light, and the general light source radiates in all directions, and the intensity will gradually decrease as the distance increases; the laser emitted by the laser is inherently emitted in one direction.
Third, the laser is extremely bright and can illuminate objects at long distances. Ordinary lasers emitted by scientists using ruby lasers produce illuminance on the moon of about 0.02 lux, with bright red colors, and the laser spot is visible to the naked eye. However, the most powerful searchlight is used to illuminate the moon, which cannot be detected by human eyes.
Fourth, the laser is a monochromatic light, and its color depends on the wavelength of the active material that emits the laser. Stimulating a ruby can produce a deep rose laser beam.
Lasers and our lives
Laser technology involves many disciplines such as light, electricity, materials, and detection. Although it was born from high-end scientific research, it has long faded out of mystery and has already entered our lives.
1. Medical Field
Lasers are increasingly used in the beauty industry, such as removing freckles, age spots, tattoo removal, eyeliner washing, eyebrow washing, scar treatment, etc .; laser surgery does not require hospitalization, small surgical incisions, no bleeding during the operation, and light trauma; For the treatment of vascular skin diseases, it is highly accurate and safe without affecting surrounding neighboring tissues.
2、Laser communication
Laser communication refers to a communication method for laser transmission in atmospheric space. First, the information is converted into an electrical signal, which is then modulated by a light modulator onto a laser beam generated by a laser, which is then transmitted through an optical antenna. Atmospheric laser communication has a large capacity and good confidentiality, and is not affected by electromagnetic interference.
3、 laser speed measurement
Perform laser ranging twice with a specific time interval on the measured object, obtain the moving distance of the measured object during the period, and obtain the moving speed of the measured object.