A laser is an optical device that produces coherent radiation. The term “laser” is an acronym: Light Amplification by Stimulated Emission of Radiation. A typical laser emits light in a narrow, low-divergence beam and with a well-defined wavelength. I’m not going to get to messy with the theory.
Everyone must of seen a laser pointer so you know how it looks and what it can do. It’s a fact that ordinary laser pointers can’t burn anything. There are a few commercial lasers that will burn various stuff but those are to expensive, we are looking a cheaper way to burn stuff with a laser. Some people managed to build this kind of lasers. At your own risk you can follow their instructions, but be careful laser’s are dangerous!
Almost all of the laser’s from the following movies are based on this tutorial Link.