RDWorks Learning Lab 217 Do Laser Lenses Meet Specification

My recent understanding of the mechanism by which laser beams cut, has had knock on effects that help solve other issues that I have been struggling with. In particular I have never been able to get even close to the spot sizes claimed for various focal length lenses. I have known for many years that the idea of a fixed focal point for our laser machine lenses was a myth but never understood why. It is easily proven that changing speed or power can affect the "focal point", thus proving it must be something other than a light ray focal point which is fixed when the lens is designed. With my new found knowledge of the cutting mechanism, I now understand why the spot size and other claimed lens properties are so exaggerated and impossible to achieve. A normal light beam carrying image information can be manipulated and tamed by one or more lenses, however, although a laser beam obeys the same laws of physics, the peculiar non-uniform INTENSITY within the beam exploits weaknesses inherent within the spherical lens design.