The laser pointer pulls the distance between you and the stars

The star pen generally uses a green laser pointer. The working medium of the laser pointer is divided into solid (such as lithium cesium triborate crystal) and gas (such as carbon dioxide). The green light is generally solid-state laser, and the main components are excitation source, condensing cavity, and resonant cavity mirror. For astronomical pointing stars, the beam emitted by the Laser pointer is a very beautiful green line, which is very suitable for observing the starry sky at night and can point out the position of the stars. Ordinary stargazers use the pointing star pen because it is easier to use than your fingers. It is not so easy to understand which star you are referring to when you point your finger at a certain star. It is much better to use the pointing star pen, after all, laser The beam is very thin. When the laser is scattered by impurities in the air, it can leave a bright light path. If you look at the night sky along the direction of the laser light path, the error will be much smaller. Sodium atoms can emit a laser beam with a wavelength of 589.2 nanometers after being stimulated, and there are a small amount of natural sodium atoms in the earth’s atmosphere about 90 kilometers high. When these sodium atoms receive light waves of this wavelength, they can Absorbing these light waves and then releasing them again is equivalent to lighting a lamp at a height of 90 kilometers. This lamp sends the light to all directions, some of which return to the ground and are observed by the astronomical telescope. Its brightness It is bright enough to be used as a guide star for an adaptive optics system. Astronomers have explored an adaptive optics system that can automatically counteract the interference caused by the atmosphere, but this system requires a sufficiently bright guide star as a basis for correction, but there is usually no such star in the sky, so Someone thought of using a laser to artificially create a bright star. For example, sodium laser guide star.

As long as it emits green light, you can definitely see a bunch of straight and bright “green lines” pointing towards the sky when you shoot it toward the sky. It can be seen that the choice of Green laser pointer mainly focuses on light color, not power. In fact, high-power laser pointers are relatively large in size, and their portability is relatively low. They are mainly used in complex environments with strong light interference (such as daytime or bright exhibition halls). It is meaningless to refer to stars. Yes, after all, there is no glare interference in the night sky. Ordinary light sources will scatter. To allow light to propagate in a specified direction, it is necessary to equip the light source with a condensing device so that the light radiation can be collected before it can be emitted in one direction. The laser light emitted by the laser is naturally emitted in one direction.