Carbon Dioxide Laser

The carbon dioxide laser is a gas laser that uses the energy difference between rotational-vibrational energy levels. Within the vibrational levels of CO₂ there are rotational sub-energy levels. A mixture of N₂ and CO₂ gas are placed inside a chamber. The N₂ atoms are excited through an electrical pumping mechanism. The excited atoms then collide with the CO₂ atoms transfer energy. This transfer of energy causes the CO₂ to go into a higher vibrational level. The excited CO₂ molecules then go through spontaneous emission when they are relaxed to lower rotational-vibrational levels increasing the signal of the incident light . Carbon dioxide lasers are extremely efficient, around 70%, and powerful compared to other gas lasers making them useful for welding and cutting.

Figure 1. Schematic of carbondioxide laser