THE ROLE OF MOLECULAR-COMPLEXES IN A HOLLOW-CATHODE CW HECD+ LASER

The importance of molecular complexes in gas discharge lasers has long been recognised, and indeed they are the essence in excimer lasers. F or other discharge lasers operating with gas mixtures, for example met al vapour lasers, the role of molecular complexes in the laser dischar ge has hardly been addressed. In this work the emission from a cw mult i-colour hollow-cathode HeCd+ laser has been investigated spectroscopi cally, and emphasis was placed on the detection of molecular bands. Sp ecifically the presence of He2 in the laser discharge was confirmed w hich is thought to play a major role in the generation of the green la ser lines. Emission bands attributed to the Cd2 metal dimer were iden tified; however, this dimer does not seem to be of importance in the l aser process. In addition to the He2 and Cd2* emission strong molecul ar continuum bands, exhibiting gain, were observed which accompany all laser lines; these can only be interpreted as originating from transi tions in the ionic complex (He..Cd+).