Methanol laser lines from torsionally excited co stretch states, and from OH-bend, CH3-rock, and CH3-deformation states

Abstract

Using a quasi-CW CO2 oscillator-amplifier combination with peak power 300 Watt, we have generated FIR laser emission in weak absorption bands of CH3OH. 40 new lines are reported, and their wavelengths are measured with a relative accuracy of 5×10−5. A total of 72 lines are assigned. 34 of these involve torsional n=1, 2, and 3 states of the CO stretch and the vibrational ground state. The remaining lines are associated with the CH3-rock, OH-bend, and CH3-deformation modes. The latter are located 1460 cm−1 above the ground state, and are pumped by simultaneous vibrational excitation and torsional deexcitation.