American scientists put forward the laser principle in 1958, and American scientists Luo Xiao and Downs put forward the "laser principle", that is, when a substance is excited by the same energy as its molecular natural oscillation frequency, it will produce this kind of non-divergent strong light-laser. He published a paper for this purpose and won the 1964 Nobel Prize in Physics.

The main content of this theory is that there are different numbers of particles (electrons) distributed in different energy levels in atoms that make up matter. When a high-level particle is excited by a photon, it will jump from the high-level to the low-level level. At this time, they will emit light with the same properties as the light that excites them, and in a certain state, weak light can also excite strong light. This is called "optical amplification of stimulated radiation", or laser for short.

Introduction:

Laser is another great invention after nuclear energy, computer and semiconductor since the 20th century. It is called "the fastest knife", "the most accurate ruler" and "the brightest light".

The light excited by atoms is named "laser": after absorbing energy, electrons in atoms jump from low energy level to high energy level, and then fall back from high energy level to low energy level, and the released energy is released in the form of photons.

Laser is widely used, including laser marking, laser welding, laser cutting, optical fiber communication, laser ranging, laser radar, laser weapons and so on. Laser system can be divided into continuous wave laser and pulse laser.

Above content reference: Baidu Encyclopedia-Laser