Two methods are described for reducing or eliminating the background of single-beam spectra obtained by Fourier transform spectrometers incorporating analog data-reduction systems. One method simply involves increasing the amplifier gain so that the central spike of the interferogram is clipped. The second method involves the use of an electronic device which eliminates the central part of the interferogram. Both methods lead to spectra having flat backgrounds, but distortion of the spectrum may also be caused.
H. Mark and M. J. D. Low, "Background Elimination in Spectra Generated by Fourier Transform Spectrometers," Appl. Spectrosc. 25, 605-608 (1971)