This can virtually eliminate oxidation and produces edges that are free from charring. Acrylic is a good example of a material that vaporizes easily and does not tend to oxidize. For thicker non-metallic materials, such as wood, the heat of laser cutting can produce secondary oxidation and charred edges are more difficult to eliminate. For thicker materials the HAZ is larger and it is more difficult to remove all of the oxygen. Wood also can contain moisture and oxygen which will increase the burning.
Metal cutting with a laser is a very different process.
To cut metal, oxygen assist is sometimes used to increase the burning and help remove material. This operates somewhat like a small-scale acetylene torch. In general, non-metallic materials are good absorbers of infrared energy as produced by a CO2 laser. Likewise, they are generally poor conductors of heat and have relatively low boiling temperatures. As such, the energy intensity of a focused beam is almost totally transmitted into the material at the spot and will instantly vaporize a hole.