CO(v = 2:1) laser transitions from He-air-CH4

A flowing electrochemically excited liquid-nitrogen-cooled He-air-CH
4
-(CO) laser was operated in
Q
-switched fashion yielding 20 CO laser lines below 5.0 μ. These laser lines were measured to occur from 4.7848 to 4.9880 μ. The lines were all identified to result from
P(J)_{\upsilon,\upsilon'}
CO vibrational-rotational transitions as low as
\upsilon = 2:1
. Nine such
\upsilon = 2:1
transitions were measured.