Signature variations with mirror separation for small sealed CO2lasers

A detailed experimental study of laser signature as a function of laser mirror distance variations is reported. This was done for small sealed low-power CO2lasers (≈ 1 watt) of the type useful in laser communication. It is shown that most laser-output profiles change drastically from half-wavelength to half-wavelength except the strong P(20) line, which seems to remain relatively constant. Frequency width is given for many of the laser output profiles appearing in the various signatures observed. Line competition is also discussed.