Abstract
The grating spectra of several gases subject to periodic pressure variations have been studied in the near infrared. In the modulated spectra the absorption lines associated with transitions between the higher rotational levels are enhanced as compared with the corresponding lines in conventional spectra. This effect is interpreted in terms of periodic population and depopulation of the upper rotational levels as a result of temperature variations occurring during the modulation cycle. Quantitative comparison of the observed total absorption of the lines of the R-branch of the CO fundamental with the total absorption calculated on the basis of an adiabatic cycle was satisfactory. Possible application of pressure modulation techniques to other problems of infrared spectroscopy is discussed.
© 1959 Optical Society of America
Full Article | PDF ArticleMore Like This
James C. Gilfert and Dudley Williams
J. Opt. Soc. Am. 48(11) 765-769 (1958)
Richard R. Patty and Dudley Williams
J. Opt. Soc. Am. 52(5) 543-545 (1962)
J. N. Howard, D. E. Burch, and Dudley Williams
J. Opt. Soc. Am. 46(4) 237-241 (1956)