Short-wavelength far-infrared laser cavity yielding new lines in methanol.

We report 16 new laser lines generated in a short-wavelength far-infrared Fabry–Perot laser cavity. The CO2 pump laser is coupled into the far-infrared laser outside the far-infrared laser mode, and the cavity uses a 45° adjustable output coupling mirror; this combination results in a low-loss Fabry–Perot cavity for wavelengths below 150 μm. The new lines are of medium and strong intensity and have wavelengths in the region 26.2–125.7 μm.