A CO plasma can be excited to a strong vibrational disequilibrium by CO las
er radiation. From such an optically pumped CO plasma, we have been able to
observe CO laser emission. This type of new excitation mechanism for the C
O laser will provide a very good means to study relaxation processes in a r
unning laser under much better defined experimental conditions than in gas
discharge lasers. (C) 1998 Elsevier Science B.V. All rights reserved.