Optically pumped far-infrared laser lines of methanol isotopomers:: 12CD3OH, 12CH3OD, and 12CH2DOH

Twenty-seven new FIR, far-infrared, laser lines from the isotopomers of methanol: (CD3OH)-C-12, (CH3OD)-C-12, and (CH2DOH)-C-12 were obtained by optically pumping the molecules with an efficient cw CO2 laser. The CO(2)laser provided pumping from regular, sequence, and hot-band CO2 laser transitions. The 2 m long far-infrared cavity was a metal-dielectric waveguide closed by two, hat end mirrors. Several short-wavelength (below 100 mu m) lines were observed. The frequencies of 28 laser lines observed in this cavity (including new lines and already known lines) were measured with a fractional uncertainty limited by the fractional resetability of the far-infrared laser cavity, of 2 parts in 10(7).