Focusing a Laser Cutting Beam

Laser cutting is carried out on a range of materials for many different purposes. While some of those functions have been discussed here, the specifics about how the laser beam itself is rarely discussed. So this post looks at just that, and how a laser cutting beam is focused.

A special lens is used to focus a beam, additionally a curved mirror can be used, but it all takes place in the laser cutting head.

The beam is precisely focused so that the shape of the focus spot and the density of the energy in that spot are perfectly round and consistent, whilst centred in the nozzle.

Focusing the large beam down to a single pinpoint causes the heat density to increase to a high degree. Much like using a magnifying glass to focus the sun’s rays onto a leaf, which can start a fire, Focusing 6 KWatts of energy into a single spot works in the same way.