5. Laser cutting

5.1 Principle

The principle of L.A.S.E.R. (Light Amplification by Stimulated Emission of Radiation) is the discharge of electricity of a few million volts which activates, between two electrodes, a gaseous mixture (carbon dioxide CO ₂ for example) at a pressure of several millibars. The device (figure 8 ) is enclosed in a glass tube that only lets out a beam of a precise wavelength (10.6 mm in the case of the CO ₂ laser).

This beam is reflected by a set of mirrors to a movable cutting head, then focused by a lens on the material to be machined. Focusing the beam gives a focal diameter...