After the release of “Star Wars 7”, Yiqi Juechen, swept the major box office records with great momentum. There is nothing in the movie that makes fans think more than the powerful lightsaber that can put the enemy to death. Owning such a sword must be the dream of all iron fans.
It is said that although officials have repeatedly explained that the lightsaber is a mass of plasma and is bound into the shape of a sword by a strong magnetic field, it still cannot stop a large number of fans from buying laser pointer swords frantically. Wait a minute, the lightsaber in Star Wars is not made of lasers?
Most people know that the English name of laser is LASER. Here, we have to move out the very smart big physicist Einstein. Because the basis of laser comes from the theory he put forward. In 1917, the famous Einstein proposed a new set of technical theory: the interaction of light and matter. Everyone knows that matter is composed of atoms and molecules.
Atoms and molecules also carry electrons. These particles have different energy states (energy levels). The theory is that there are different numbers of particles (electrons) in the atoms that make up matter, and they are all at different energy levels. Some have high energy levels and some have low energy levels.
Particles at high energy levels are excited by some kind of photon from outside, and they will jump from high energy level (E2) to low energy level (E1). At this time, light with an energy of ΔE will be radiated, and the radiated light happens to have the same frequency and direction as the light that excites it. In a certain state, we can also excite a strong light through a weak light. This phenomenon is called “light amplification by stimulated radiation”, or green laser pointer for short.