Like other gas lasers, the CO2 laser's working principle and its stimulated emission process are also more complicated. Molecules have three different motions, that is, the motion of electrons in the molecule, and its motion determines the electronic energy state of the molecule; the second is the vibration of atoms in the molecule, that is, the atoms in the molecule constantly vibrate periodically around their equilibrium position-and It is determined by the vibrational energy state of the molecule; the third is the rotation of the molecule, that is, the molecule rotates continuously in space as a whole, and this movement of the molecule determines the rotational energy state of the molecule. The molecular motion is extremely complicated, so the energy levels are also very complicated.