Observation and assignment of large offset farinfrared laser lines in CH3OH optically pumped by a CO2waveguide laser

Four new FIR laser lines at 62.98, 48.77, 224.53, and 190.65 μm are reported from CH
3
OH, optically pumped by the 10R34 and 9R10 lines of a waveguide CO
2
laser. Measurements performed by several techniques confirm that the pump offsets are outside the tuning range of conventional CO
2
lasers. Two of the lines are assigned as high
J
transitions within the torsional ground state of the CO stretch.