Revised molecular parameters for 32SO232SO2 and 34SO234SO2 from high resolution study of the infrared spectrum in the 7–8μm wavelength region

The absorption spectrum of SO2 has been studied with 2 MHz instrumental resolution in the wavenumber range 1315–1395cm-1, using a difference frequency spectrometer based on diode lasers for the 1300 and 1550 nm telecom bands. Initially, Lorentz broadening parameters are determined, at pressures up to 400 Pa, for 545 lines covering lower state J up to 60 and KaKa up to 14. Using this information in conjunction with spectra recorded at 100 and 200 Pa the line strength is subsequently determined for 395 lines of the (000)→(001) band of 32SO2, 170 lines from the (010)→(011) hot band of 32SO2, and 98 lines from the (000)→(001) band of 34SO2, and dipole moments are derived for all three bands. For the hot band, line positions of 178 transitions are measured and merged with previously published data to produce an improved set of Hamiltonian parameters for the (011) state, using the most recent model for (010).