Effects of strong vibrational excitation in water vapor spectroscopy
High-sensitive spectrometers, created at IAO SB RAS for studying highly excited states, are described. The spectrometers include a Fourier spectrometer with a multipath absorption cell and spectrometers that use modern methods of highly sensitive laser spectroscopy (intracavity laser spectrometers, spectrometers with a high quality external cavity). Designed spectrometers have a high spectral resolution (0.01…0.001 cm <sup>-1</sup>) and high sensitivity to absorption (10 <sup>-7 </sup>- 3 × 10 <sup>-9</sup> cm <sup>-1</sup>), which makes them promising for the study of parameters of spectral lines arising from transitions to high-energy vibrational-rotational states. The effects of the vibrational-rotational dynamics related to the chaotic behavior under strong excitation are considered by analyzing spectra of water vapor. They are: an anomalous centrifugal distortion, HEL-resonances in H <sub>2</sub>O, the nn <sub>3</sub> highly excited states of the HD <sup>16</sup>O, the vibrational dependence of the line contour parameters, and the effect of intramolecular resonances on interference lines.