GHOSTS AND ARTIFACTS IN FOURIER-TRANSFORM SPECTROMETRY

Ghosts in Fourier-transform spectrometry are important for three reaso ns: they can give rise to spurious coincidences of frequency differenc es in spectral analysis, distort the phase correction, and set a limit to the attainable signal-to-noise ratio. The various types of ghost, originating from amplitude modulation, phase modulation, and intermodu lation, are described and discussed, together with some hardware and s oftware artifacts. Recipes are given for identifying these features an d, where possible, avoiding harmful effects from them. (C) 1996 Optica l Society of America