Michelson interferometer, throughput

The maximum optical throughput for a Michelson interferometer, 0 is given by max 6... 

It should be noted further that an increase in resolution is easily achieved in this case by increasing the maximum path difference and the scanning time. The power flux is not influenced by an increase of Smax- However, there will be an increase in noise, as we shall see later. An increase in resolution means for a grating instrument a reduction of slit width and hence, a reduction of the power flux, which is proportional to the square of the slit width [see Eq. (5.12)]. It also seems worth mentioning that the Jacquinot or throughput advantage exists not only in the Michelson interferometer but also in other instruments, e.g. a Fabry-Perot interferometer. 

For all Fourier spectrometers discussed here, the aperture or the /-number is listed in Table 3. As usual in optical instruments, the /-number is the ratio of the diameter of a lens or a concave mirror and its focal length. For example, //4 means that the focal length of the lens or mirror is larger by a factor of 4 than the diameter. In case of a Michelson, interferometer, let us refer the /-number to the collimator mirror, i.e. its diameter and its focal length. Obviously, the ratio of these two quantities is a measure of the solid angle subtended by the collimator mirror as was pointed out in Section 5.1 in context with the throughput of the interferometer. We recall that... 

Most modem IR spectrometers are Fourier transform (FT) instmments based on a Michelson interferometer. FT instruments offer significant benefits in analysis time, throughput and wavenumber reproducibility over grating spectrometers. FT theory and instmment design is beyond the scope of this chapter and is covered in depth in the literature [10]. 

ABSTRACT. The construction and operation of a Michelson interferometer that permits Fourier transform photoacoustic spectroscopy of opaque and partially transparent samples at visible wavelengths is described. Multiplexing and throughput advantages are considered. A visible spectrum of Nd(III) doped laser glass is reproduced and potential kinetic applications are described. 

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