When I saw a block of glass with a 3D engraving, I wondered how something like this could be made and I began investigating this question. I found that a laser is used to write points in 3D by burning the material. One point in space (in the glass block) can be written by crossing several laser beams so that the temperature at the intersection becomes high enough to write the point. Another possibility would be to focus a laser beam with a lens to write a point at the focal spot. I found this interesting and therefore I decided to attempt to built a 3D laser engraving device.
