We have made what we think is the first observation of the oscillation
of the 9-mum hot-band lines 01(1)1 --> [11(1)0, 03(1)0]II of CO2. We
have observed 40 lines with a maximum power of 8 W. They will provide
a new source of laser radiation for spectroscopy. The set of lines has
been positively identified by directly measuring the frequencies of t
wo of the lines with a heterodyne technique using a CO2 laser standard
.