DDM Laser

Light Amplification by Stimulated Emission of Radiation

Laser Cutting Theory


This section discusses the criteria which are important to successful cutting. It is intended as a guide only, since there is no substitute for operator experience.

These are the principal considerations with which the operator must concern himself at all times. Note that the various items are not independent; it is the combined effect of these adjustments which determines the results.

Laser Power Setting
The most important point regarding laser power is that maximum power is not necessarily beneficial. Firstly, there is some trade-off between power and mode – the mode (or quality of the beam, which determines the fineness of the focus) is of significantly greater importance to cutting than the power level. Secondly, limiting the power is frequently beneficial in terms of reducing thermal input into the material – especially when cutting thin material, or materials which can be adversely affected by excess heat. It is simply wasteful to use more power than necessary.

Cutting Speed
The actual feedrate in use for a job will directly affect the cutting results; the feedrate is decidedly a function of the type of material and material thickness to be used. In any particular case, there will be some feedrate which is too high and the cut will simply fail to penetrate the material fully; at the other extreme, excessive heat input is likely to damage the material adjacent to the cut. In general, some feedrate closer to the maximum limit will be optimum, but always the choice is made experimentally on the basis of cutting results; the operator, with a little experience, can make this determination quite readily, making use of the feedrate override control.