How does a laser cutter work?
The Basic Industrial Laser
Lasers used for cutting are rarely found outside of industrial use, as they are extremely dangerous and very large. Laser cutting is done by CO2 lasers or neodymium lasers. CO2 lasers function by energizing a gas mixture of carbon, nitrogen, hydrogen and helium. Neodymium lasers function in the same way as CO2 lasers, except instead of using gas as the medium, they use a crystal with small amounts of neodymium in it.
The Modification of The Laser Beam for Cutting
Simply shining a CO2 or Neodymium laser at an object will not cut or engrave it with much accuracy. Hence, these laser beams are focused with lenses, similar to how a child focuses the sunlight with a magnifying glass to burn ants. However, in this case, the light being focused is extremely powerful and can cut through hard steel. As the laser focuses, it draws near to 1/8 inch in diameter, making it suitable to cut steel. However, the heating up of the steel doesn't just make a cut appear and the steel disappear, there must be methods for removing the steel or other material that is cut away.
The Methods of Laser Cutting
There are many ways to cut with a laser. In many cases, a highly concentrated spray of gas or water is sprayed right behind the laser to blow out the recently cut steel, leaving a nice, clean cut. Another method used involves heating the material to its boiling point and vaporizing it; however, this can only be done with materials that do not melt, such as wood. A final method involves cracking very brittle materials with the heat of the laser beam then directing that crack with the heat of the laser beam to make cuts.