High-accuracy Doppler-limited 10(6) samples Fourier transform spectroscopy.

The contribution of the third-generation Fourier spectrometer, built at the Laboratoire Aimé Cotton and currently at the Laboratoire d'Infrarouge, to meteorological and high resolution Doppler-limited measurements is reported citing typical examples and the latest instrumental improvements. A tilt-compensated triple-pass system for use with previously built Fourier spectrometers to increase the resolution by 3 is described. The resulting width of the apparatus function of the triple-pass third-generation interferometer is better than 10(-3)cm(-1) and can be meaningfully expressed in frequency units. Its actual value is 27 MHz. For the first time a spectrometer is able to give very wide spectral range information with a resolving power sufficient to analyze sub-Doppler spectra.