Vol. 26, issue 03, article # 11

Abstract:

This paper describes a highly sensitive spectrometer in the range 20000-9000 cm^-1 with an absorption sensitivity of 1×10^-8 cm^-1 and a spectral resolution of 0,05 cm^-1, created on the basis of Bruker IFS-125M Fourier spectrometer with a small multipass cell. The high sensitivity of the spectrometer was achieved through the use of the multipass absorption cell (base length is 60 cm) with a high aperture ratio (the ratio of the diameter of the collective mirror to the base length is 1:4) and a high intensity light source. A comparison of the recorded spectra with the experimental and theoretical spectra of the water vapor shows that the spectrometer reliably detects the presence of absorption lines of natural isotopomers of water. The threshold sensitivity of the spectrometer was defined from the signal/noise ratio and from the recorded water lines with minimal intensities.

Keywords:

Fourier transform spectroscopy, multipass cell