Jacquinot advantage, Fourier transform spectroscopy

There are three well known advantages one gains by doing Fourier transform spectroscopy that are usually discussed in terms of their relationship to grating spectroscopy. They are called the Fellgett advantage, the Jacquinot advantage, and Connes accuracy. 

In detector noise limited spectroscopies such as PAS it is advantageous to enhance the throughput of energy (Jacquinot s advantage) by utilizing a Michel son interferometer. One then Fourier transforms (FTs) the resulting interferogram to yield a PA spectrum that qualitatively resembles an absorption spectrum. 

As mentioned in the introduction to this chapter, visible/UV Fourier transform instruments are still found mainly as unique, one-of-a-kind instruments in a few spectroscopy laboratories. The research topics being pursued with these Fourier transform instruments include atomic spectrochemical measurements, atomic and molecular emission spectroscopy from hollow cathode discharges, and molecular absorption spectroscopy for accurate frequency standards and molecular constants. In each of these research efforts, the Fourier transform method has proven useful. In part, the success of this method is derived from the fundamental advantage originally stated by Jacquinot, and to some extend from the advantage stated by Fellgett. 

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