Fourier-transform infrared spectroscopy spectrometer with Michelson

The modern spectrometers [7] came with the development of the high p>erformance Fourier Transform Infrared Spectroscopy (FT-IR) with the application of a Michelson Interferometer [10]. Both IR spectrometers classical and modern give the same information the main difference is the use of Michelson interferometer, which allows all the frequencies to reach... 

It must be emphasized that IR spectroscopy has undergone major improvements in terms of light sources, detectors, and data systems, and particularly in developments of the Fourier transform technique which utilizes interferometers instead of salt prisms and grating monochromators. Modern commercial spectrometers operating with the aid of a Michelson interferometer produce interfero-grams which, upon mathematical decoding by means of Fourier transformation, deliver simultaneously whole absorption spectra that are commonly referred to as Fourier transform infrared FTIR) spectra. 

Summarizing the results of our discussion of the practice of Fourier transform spectroscopy, we start with the presumption that the equipment for most routine spectroscopic investigations consists of a Fourier spectrometer with a Michelson interferometer and a digital computer. In other words, the advantages of the lamellar grating used as a two-beam interferometer, and of phase modulation, for example, have been utilized only for certain special applications in the extreme far-infrared. All commercial Fourier spectrometers are available with a computer attached, which in most cases not only performs the Fourier transform but is also programmed to control the instrument. Commercial instruments have a remote switch for the selection of the different spectral ranges, and the filters and beams... 

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