Methanol spans far infrared

IEEE J. Quantum Electron. 50, 23–24 (2014)

Sumaya Ifland from Edmonds Community College and co-workers from Central Washington University in the USA have successfully generated 43 new emission lines in the far-infrared range (106.4 μm to 700.3 μm) by optically pumping an isotopic form of methanol, ¹³CHD₂OH. This is the first time that laser radiation above 100 μm has been generated from this particular substance. The researchers found these emissions by varying the length of the cavity of the molecular laser system and pumping the cavity using a carbon dioxide laser. The far-infrared laser emissions were detected using a liquid-helium-cooled silicon bolometer operating at a temperature of 4 K. Previously, eight laser lines of ¹³CHD₂OH had been identified at wavelengths below 100 μm. The newly discovered emissions above 100 μm suggest that ¹³CHD₂OH is promising as an optically pumped laser medium, especially for generating terahertz radiation for spectroscopic applications.