Table of Contents
Laser Chemistry
Volume 13, Issue 1, Pages 63-83

The Role of Molecular Complexes in a Hollow-Cathode CW HeCd+ Laser

1Department of Physics, University College Swansea, Singleton Park, Swansea SA2 8PP, United Kingdom
2Centro de Investigaciones en Optica, A.C., Gto., Leon 37000, Mexico
3Department of Physics, Faculty of Mathematics and Science, Gadjah Mada University, Yogyakarta 55281, Indonesia

Received 16 December 1992; Accepted 19 January 1993

Copyright © 1993 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The importance of molecular complexes in gas discharge lasers has long been recognised, and indeed they are the essence in excimer lasers. For other discharge lasers operating with gas mixtures, for example metal vapour lasers, the role of molecular complexes in the laser discharge has hardly been addressed. In this work the emission from a cw multi-colour hollow-cathode HeCd+ laser has been investigated spectroscopically, and emphasis was placed on the detection of molecular bands. Specifically the presence of He2 in the laser discharge was confirmed which is thought to play a major role in the generation of the green laser lines. Emission bands attributed to the Cd2 metal dimer were identified; however, this dimer does not seem to be of importance in the laser process. In addition to the He2 and Cd2 emission strong molecular continuum bands, exhibiting gain, were observed which accompany all laser lines; these can only be interpreted as originating from transitions in the ionic complex (HeCd+)*.