1. Coherent beam of light.
2. Monochromatic light, then a specific wavelength.
3. Very high brightness.
The very high brightness is the predominant cutting feature resulting from a high power concentrated in a narrow beam of light.
The other two features, the consistency and the monochromatic aspect, make the laser marking able to perceive movements of the order of micrometers and therefore very useful for automated precision jobs.
Mechanism and function
To cut tubes or plates carbon dioxide laser is preferred for its ability to develop a great power, so that the relationship between the pumping power and the power emitted by the laser reaches even 20%.
The wavelength is between 9.4 and 10.6 micrometers.
The mechanism by which laser can cut the pipe is given from the issue of the light beam created using the energy of the excited electrons of the carbon dioxide molecules.
The laser tube contains inside a gas mixture made up mainly of carbon dioxide and nitrogen with the remaining parts consisting of oxygen and helium.
The mechanism starts with an electrical discharge through the laser tube colliding nitrogen molecules with each other.
Nitrogen, unable to quickly get rid of the absorbed energy by emitting a photon, transfers energy to the electrons of the carbon dioxide that ' to discharge' will emit a photon, thus establishing the laser beam.
The carbon dioxide laser emits an infrared light beam and the tube can not use materials such as glass lenses and mirrors, since at that wavelength the glass is not transparent.
So to solve the problem laser tubes are constructed by using lenses of molybdenum and germanium output mirror (you can also find many other cheaper materials).
Once we used to use mirrors made of salt but they were impractical since they caused problems like deformation and deterioration due to moisture.