Suppression of transverse modes of a CW CO<inf>2</inf>laser by cavity length control

The described technique of transverse mode control makes use of the small transition linewidths of the CW CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> laser. The laser medium itself is used for spectral discrimination. The method was tested and found to be superior to the usual technique of using an intracavity iris.