A CO2 laser has been designed to provide a relatively simple portable unit that generates coherent light pulses at selected infrared wavelengths. This improved laser was originally designed for the detection of air pollutants. Other applications of this laser would include optical communication and research in infrared transmissive materials. This laser is de-signed for sealed-off operation and high-power repetitive pulsing at selected wavelengths. Earlier systems for pulsing a CO2 laser have employed prisms or gratings within the laser cavity to shift the output from one infrared line to another. However, these systems in addition to being rather cumber-some, and difficult to manipulate, significantly reduce the power output of the laser.