Extensive measurements of gain in the Xe III system initially observed by Kapteyn et al. (1986) is reported. The dependence of this gain on pressure, pumping-pulse length, and pump energy is presented. By optimizing these parameters, a gain of exp(3.2) was achieved by using only 0.56 J of 1064-nm energy on target, representing an efficiency improvement of nearly 100. Total gains as high as exp(6.6) have been measured when using higher energies. The data indicate that effective laser-produced plasmas can be created with applied power densities as low as 5 x 10 to the 10th/sq cm.