Abstract The spectral output of a ruby laser may contain a large number of discrete frequencies which correspond to different allowed modes of the laser cavity. All these modes lie within the spectral line width of the laser line. It was the purpose of the present study to introduce mode selective elements into the cavity in order to reduce the number of modes in the laser beam. The approach was to build a conventional laser cavity with plane parallel mirrors and to couple a short resonant...

Abstract Measurements of the gain in an amplifier discharge tube containing a fixed composition, 1:1.5:5.6, Co₂-N₂-He gas were made under both ac [sic] excited and pulsed discharge conditions. While the ac gain results indicated a possible increase in gain with increasing current densities, the pulsed discharge experiments failed to bear out this extrapolation. Instead, the gain reaches a limit that is apparently...