Fourier transformation and light dispersion for spectra analysis

[xhtp2000]

IR and NIR spectroscopy usually employ Fourier transformation to separate the signal into individual wavelength, UV and Vis spectroscopy normally apply gratings for light dispersion (into individual wavelength). What is the cutoff wavelength, and why is so?

 

[Andy Resnick]

Are you referring to FTIR spectroscopy?

 

[christopher.s]

I don't think there is any inherent cutoff frequency when dealing with FTIR spectroscopy. Normally your spectral response will be determined by; A) your source. sometimes a tungsten globar or similar; B) your beamsplitter; C) your detector.


there is a lot of pertinent information here

 

[xhtp2000]

Are you referring to FTIR spectroscopy?

Yes, for instance, FTIR uses Fourier transformation to convert the signal into individual wavelength, but Vis spectroscopy, like laser-induced breakdown spectroscopy, uses gratings to disperse the light into individual wavelength, I want to know if I can interchange this two techniques for light dispersion .

 

[Andy Resnick]

Yes, for instance, FTIR uses Fourier transformation to convert the signal into individual wavelength, but Vis spectroscopy, like laser-induced breakdown spectroscopy, uses gratings to disperse the light into individual wavelength, I want to know if I can interchange this two techniques for light dispersion .

Christopher.s' link has a nice explanation of the lower wavelength limit in FTIR machines.