CARBON  DIOXIDE  LASERS

    The carbon dioxide laser is about as close to the “death ray” of classic science fiction as it gets. At an infrared wavelength around 10.6 μm, the beam is readily absorbed by most materials and readily converted into heat. Power outputs range from big (compared to most common lasers, such as the HeNe) to enormous, with power outputs in excess of 50 kW possible! Even the smallest lasers output several watts, enough to burn many materials on contact with the beam. Aside from high power outputs, the other distinguishing feature is high efficiency, with typical efficiencies of industrial lasers being over 10%. These features combine to make the CO₂ laser the de facto standard materials processing laser, with applications including cutting and welding of such materials as hardened metals and ceramics. There are a variety of forms of CO₂ lasers, based on tube design. Many small lasers resemble any other gas laser, being a glass tube with two cavity optics, while larger lasers may resemble an excimer in structure, with long, transverse electrodes.