Focal Lengths of CO2 laser lenses.
What is focal length: Se called distance to one of the lens parameters, when the laser light beam is concentrated, an inverted double cone effect is produced, where the central point between the 2 cones or junction point is becoming the focal point or spot.
The distance between the underside of the lens and the focal point is called the focal length and is measured in inches. The greater the focal length, the greater the depth of field. In this way, a short focal lens is ideal for cutting fine materials or engraving, since the point created is smaller, in this there is more concentration of energy and we can achieve a greater definition of marking / engraving.
On the other hand, a lens with a greater focal length (lenses from 2.5 ″) will be perfect for cutting thick materials, the cut will be straight due to a smaller divergence of the laser beam, we try to cut thin materials, we We will find that it has a lower concentration of energy and a low resolution in the marking, so this type of lens is not suitable.
For wavy material, on the other hand, a long focal lens is ideal, as it has a greater depth of field with the highest and lowest areas, you can cut evenly, however, with a short focal lens, redundancy is worth the cut will not be uniform. (For more parameters consult the section on Laser lenses and mirrors in our Spare Parts section for laser machines.