New features of an FT spectrometer using LED sources

The efficiency of LED emitters in high resolution Fourier spectroscopy with a small multipass cell has been shown. Such aspects of Fourier spectroscopy as intensity of the light sources, their stability, and spectral range were considered. Using a 2.5 W LED emitter as a light source for the spectrometer with a 60-cm multipass cell during a 24-h measurement time and by optimizing a number of passes in the cell, we have achieved a signal-to-noise ratio of 1 x 10(5) which corresponds to a minimal detectable absorption coefficient of 6 x 10(-9) cm(-1). This made it possible to determine the parameters of water vapor lines with the intensity of 2 x 10(-28) cm/molecule. The absorption spectra of H2O and CO2 isotopologues in the range of 10,000 to 23,000 cm(-1) were recorded using high sensitivity Fourier spectrometer. (C) 2016 Elsevier Ltd. All rights reserved.