Working Principle of CO2 Laser source
In the wood, leather and paper marking industry, we all know about CO2 laser marking machine, but for CO2 laser marking, the working principle of laser may not be clear. Next, we will analyse the application of laser professionally.
CO2 lasers are commonly used molecular gas lasers. They are also widely used in industry. CO2 lasers work with a mixture of CO2, N2 and He. Laser transitions occur between two vibrational-rotational levels of the ground state of the electron of CO2 molecule. The effect of N2 is to improve the excitation efficiency of the upper level of the laser, while He is helpful to the pumping of the lower level of the laser.
CO2 lasers emit invisible lasers of 10.6um and 9.6um wavelength. The laser can work continuously and pulsatively. Its output power and energy are large, and its efficiency can reach 15%~25%. The continuous output power of its commercial devices can reach the magnitude of 10,000 watts. CO2 laser has been widely used in drilling, cutting, welding and heat treatment in industry. It is an ideal laser in industrial application.
Working Principle of CO2 Laser Source
as other molecular lasers, the working principle of CO2 lasers, i.e. stimulated emission process, is also complicated. Molecules have three different motions:
1. The motion of electrons in a molecule determines the electronic energy states of the molecule.
Principle oscillation within a molecule, i.e. periodic oscillation of atoms around their equilibrium positions, determines the vibrational energy states of molecules.
3. Molecule rotation, that is, molecule rotates continuously in space as a whole, which determines the rotational energy state of molecule; CO2 molecule is a linear symmetric molecule, two oxygen atoms are on both sides of carbon atom. The atoms of the molecule are always moving, and their equilibrium position should be kept vibrating. According to the theory of molecular vibration,
There are three different modes of CO2 vibration.
1. Two oxygen atoms vibrate in the opposite direction along the molecular axis, that is, two oxygen atoms reach the maximum and equilibrium value of vibration at the same time, while the carbon atoms are stationary at this time, so their vibration is called symmetrical vibration.
The two oxygen atoms vibrate in the direction perpendicular to the molecular axis, and the vibration direction is the same, while the carbon atoms vibrate in the opposite direction perpendicular to the molecular axis. Because the vibration of the three atoms is synchronous, it is also called deformation vibration.
Three atoms oscillate along the symmetrical axis, in which the direction of carbon atom oscillation is opposite to that of two oxygen atoms, which is also called antisymmetrical oscillation. Among the three different modes of vibration, different groups of energy levels are determined.