ROTATIONAL STATE-SELECTED VIBRATIONAL OVERTONE SPECTROSCOPY OF JET-COOLED MOLECULES

The combination of infrared-optical double resonance excitation with infrared laser assisted photofragment spectroscopy (IRLAPS) detection permits the measurement of rotationally resolved vibrational overtone spectra of jet-cooled CF3H. The IRLAPS detection technique is sufficiently selective to be able to discriminate against the dissociation of molecules in the ground state and the upsilon(CH)=1 level used as an intermediate in the double resonance scheme. The combination of this selective detection technique with both supersonic cooling and double resonance produces J state resolved overtone spectra of the 4(2) vibrational overtone band. These spectra put a limit on the homogeneous linewidths of the rovibrational transitions of approximate to 0.5 cm(-1).