DEPENDENCE OF GAIN AND LASER POWER FOR CU-II 780.8-NM TRANSITION ON THE DIAMETER OF A SEGMENTED HOLLOW-CATHODE DISCHARGE

The dependence of laser performance and discharge characteristics on t he diameter of a segmented hollow cathode discharge for the Cu-II 780. 8 mn transition is presented, This transition has a special importance since its upper level is common to potential CW VUV laser transitions (150-170 nm), Laser tubes with internal diameters of 2, 3, 4, and 5 m m were investigated, Decreasing the diameter resulted in an increased gain for a given current (up to 100 %/m in the 2-mm diameter, 5-cm-lon g tube at 1-A current). The highest output power was obtained from the large-diameter tubes (20 mW from a 5-cm-long, 5-mm-diameter tube at 2 -A current, without optimizing the output coupler). This work is a par t of a series of investigations aimed at the optimization of the segme nted hollow cathode discharge which has already been found to be the m ost efficient type of discharge for cathode sputtered metal ion lasers .