Spatially dependent small signal gain measurements in a continuous wave rf excited Ar–He–Xe (59.5/40/0.5) gas discharge are presented. Maximum values for the small signal gain of the 2.03 and 2.65 &mgr;m xenon transitions of about 22&percent; and 37&percent;/cm, respectively, were obtained at a total pressure of 120 mbar, an input power per unit electrode area of 20 W/cm2and at a rf driving frequency of 115 MHz. With a spatial resolution better than 0.5 mm, a strongly inhomogeneous gain distribution in the transverse direction was measured. ©1997 American Institute of Physics.