Robotic cutting. Metal producing a shower of sparks as it is cut by an Yttrium Aluminium Garnet (YAG) laser mounted on a robot arm. Another robot arm at lower left holds the metal in place. By operating in tandem, three dimensional shapes can be created by the robots. Robots are ideally suited to repetitive tasks on a production line. In a YAG laser, energy is pumped into a YAG crystal which contains neodymium impurities. This energy is then produced as an intense beam of pure light. YAG lasers offer a high power output but are inefficient compared to other types.