Optical free induction decay (FID) signals of the CH3F ν4 band were observed by using a cw-OPO infrared laser coupled with a Stark switching method. The observed signals have been Fourier transformed to obtain the Lorentz functions and the widths have been analyzed to determine the pressure-broadening coefficients for rR(0,0), rQ(1,0), rR(1,0), rR(1,1), and pP(2,1) to be 1/(πT2 p) = (46.1 ± 2.1), (31.6 ± 3.6), (21.8 ± 2.5), (25.2 ± 4.0), and (26.5 ± 1.8) MHz/Torr, where T2 is the transverse decay time. The value of rR(0,0) is larger than that determined from a recent pressure-broadening measurement by 39 ± 12%. The difference is explained by collision induced reorienting transitions (ΔM = ±1, ΔJ = 0).
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry