Output characteristics of the He-Zn laser

Output characteristics of the He-Zn laser have been investigated for both fully- and quasi-continuous excitation in hollow-cathode tubes. The results illustrate the differing behaviour of laser transitions excited by Penning and charge transfer reactions (including indirect processes in the latter case). No turnover in output power with increasing discharge current has been observed for charge-transfer-excited transitions within the limits of current achieved. Total CW powers (over five transitions) exceeding 100 mW for fully-continuous and 240 mW for quasi-continuous excitation have been measured for a 3 mm-bore, 50 cm-long tube.