Study On High Precision Infrared Spectroscopy Of Nitrous Oxide

High precision spectroscopy is one of the most important methods to study the in-ternal structure and interactions of molecules,it is widely used in chemistry,physics,astronomy and environmental studies.Because of its high sensitivity,Cavity Ring down Spectroscopy?CRDS?becomes an very important method to study high precise spec-troscopy.In the thesis,CRDS based on a Ti:sapphire laser,combined with a ultra-stable etalon calibration method,was used to acquire high precision spectroscopy.First chapter of this article briefly introduces the history,development,princi-ple as well as the applications of CRDS.The ultra-stable etalon which calibrates the spectroscopy is also presented.Then brief introduction of the theory of polyatomic molecule vibrational spectrum will present in the second chapter,including vibration mode,rotation-vibration energy levels and spectral line profiles.The classification,principle,application range of the commonly used spectral profiles including Gaussian,Lorentzian,Voigt,Rautian and Galatry will be discussed in details.In the third chapter,6V3 and v2 + 6V3-v2 bands of N₂O were detected by CRDS,and more than 100 spectral lines were calibrated by the ultra-stable etalon.With the pressure linear extrapolation method,absolute positions and intensities of the ro-vibrational transition were acquired.The maximum uncertainty for the well isolated lines are considered to be 0.0003cm^-1,which is at least one order of magnitude better than that in literature.Besides,the line intensities of v2 + 6V3-v2 band were abtained for the first time.The J=20 rotational levels of the?0006?upper states were found per-turbed.In chapter four,using a cavity ring-down spectrometer with a WA-1500 wave-length meter,77 ro-vibrational transition lines of three bands of 12C16O2 molecule around 830nm have been determined with maximum uncertainty of 0.03cm^-1,which are obtained for the first time.A comparison of the measured line positions and intensi-ties of the 4003i?i=2,3,4?bands to those from AMES and GEISA line lists is given.In chapter five,the absorption spectrum of 17O richeu water lines have been recorded by cavity ring-down spectrometer between 12313-12580cm^-1.We determined 424 new lines of H₂16O and H₂17O,and corrected 56 lines of H₂16O,H₂17O and H₂18O.The results will fill the gaps of experiment data in the near-infrared wavelength.