Characteristics of rod anode type He-Cd laser tubes

The discharge and lasing characteristics of hollow-cathode He-CdII laser tubes with rod anodes have been investigated in comparison with those of a normal hollow cathode tube with pin anodes. The advantages in employing the present design are found to be high sustaining voltage, uniformity of the plasma in the axial direction, and simplicity of theoretical analysis. However, the electron density and the 23S1 metastable He density are lower in the present type, resulting in a lower lasing efficiency even in a 4-rod tube, which shows the best lasing performance. The present results indicate the importance of the electron bunching process in the cathode bore in obtaining a dense plasma. (author)