Characterization of new FIR laser lines from CHD2OH

In this work, we report new optically pumped far-infrared (FIR) laser lines from CHD₂OH. A waveguide CO₂ laser of wide tunability (290 MHz) was used as pump source, and a Fabry-Pe´rot open cavity was used as a FIR laser resonator. Optoacoustic absorption spectra were used as a guide to search for new FIR laser lines. We could observe 15 new laser lines in the range from 116.4 to 401.4 μm. The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred Lamb-dip technique was used to measure the frequency absorption transition both for the new and previously reported laser lines.