Optically pumped far-infrared laser lines and frequencies from 13 CD 3 OH

We report 26 new far-infrared laser lines from optically pumped 13CD3OH and the frequencies of 20 of these lines along with 8 other previously reported lines. Most of the new lines were pumped by regular and sequence lines of the 10R branch of a cw CO2 laser. Nine of the new lines are in the range 32–70 μm, helping to fill the gaps in this wavelength region. To our knowledge, the 32.4-μm laser line is the highest frequency of an optically pumped methanol laser ever measured with the heterodyne technique. The pump offsets for 30 laser lines were also measured (including 20 of the new lines).