Rapid-scanning Michelson

Hirschmugl CJ (1994) Low frequency adsorbate substrate dynamics for CO/Cu studied with infrared synchrotron radiation. PhD Dissertation, Yale University, New Haven, CT Hirschmugl CJ, Williams GP (1995) Signal-to-noise improvements with a new far-IR rapid-scan Michelson interferometer. Rev Sci Inst 66 1487-1488... 

In commercially available rapid-scanning Michelson interferometers, the movable mirror is scanned at a constant velocity V (cm s ). For these instruments it is... 

A Michelson interferometer with the facility for step and integrate, and rapid scan operation has been used for Fourier transform PAS. The merits of the two methods were considered. The versatility of this technique for the measurement of the infrared spectra of powdered samples has been demonstrated. Some possible reasons for the distortion of such measurements have been discussed. " FT-PAS has enabled discrimination between K N03 and K NOj and has shown the technique to be suitable for quantitative analysis of solid mixtures. ... 

An idealized Michelson interferometer is illustrated in Figure 3. The interferometer modulates the incident beam by changing the optical path difference of the interferometer. The optical path difference can be changed continuously or in increments, methods called rapid scanning and step scanning, respectively. 

Figure 8 Comparison of the resolution of a FT-IR (Michelson) spectrometer to that of a grating spectrometer. The solid lines represent the resolution of a grating spectrometer with a bandpass of 10 nm and the resolution (in nm) for a FT-IR spectrometer operating at a nominal resolution of either 4 cm- or 16 cm- (because noise levels rapidly increase for narrower slitwidths, a 10 nm bandpass is typical of analytical rapid-scanning grating spectrometers). For example, a FT-IR spectrometer operating at 4 cm- resolution has an effective bandpass of 2.5 nm at 2500 nm, falling to less than 0.5 nm at 800 nm.

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