One of the most versatile tools in a shop or makerspace is a laser cutter. The recently funded Glowforge makes having one in your garage a possibility.
With so much exciting around laser cutters, you might be wonder what is a laser anyway? There are two primary laser types: Gas and Diode. Jordan Bunker goes into detail in the Make: Skill Builder article, about the difference.
The pictures and diagrams alone are worth the look. The diagram on how a laser diode emits light is one of my favorites. (Actually, I think it is a good general purpose “led/diode diagram.”
Check out “Learn the Difference: Gas and Diode Lasers,” via Make.