The use of a Fabry-Perot interferometer for analyzing periodic spectra is described with special emphasis on the detection of rotational Raman spectra of gases. The interferograms of rotational Raman spectra have been generated experimentally by use of a specially designed air-bearing Fabry-Perot interferometer. Linear, symmetric-top and asymmetric-top molecular classes have been studied by this interferometric technique. The overall efficiency of this technique is compared quantitatively with that of a grating spectrometer. Rejection schemes, using auxiliary etalons, for reducing the effects of interfering spectra are analyzed. A computer program for simulating the Fabry-Perot interferograms has been used to study the variation of the interferogram with such parameters as gas temperature and cen-trifugal distortion constant. This interferometric technique has been used to determine the vibrational temperature, rotational temperature, and the rotation-vibration interaction constant of nitrogen gas which was heated by an electrical discharge. The possible application of this technique to the problem of remote detection of atmospheric pollutants is discussed.