Currently the most powerful continuous wave lasers available, CO2 lasers produce beams of infrared light and use gas mixture made of CO2, nitrogen, and helium. When the nitrogen molecules are excited by an electrical discharge, they collide with CO2 molecules and transfer their energy to them.
The CO2 laser wavelengths typically fall between 9–12 µm with the most common wavelength being 10,600 µm, which is suitable to a wide range of uses. Types of CO2 lasers include Transversely Excited Atmospheric (TEA), fast axial flow lasers, and sealed-tube or no-flow lasers.