Polarization effects in fourier spectroscopy. I: coherency matrix representation.

A general analytical method using the formalisms of polarization coherency and Jones's matrices is provided for the evaluation of all polarization effects in fourier spectroscopy. The method applies to any incident state of arbitrary (complete, random, or partial) polarization. Inversely, it may also be used for determining the intensity and state of polarization of the source of light. TE- and TM-mode reflectivity and transmissivity for beam splitters and the dependence of these quantities on the incident polarization are obtained. It is demonstrated that three different efficiencies for these optical components must be introduced. Interferometer efficiency expressions for the source beam and the detector beam are also derived and shown to be essentially different from the previous efficiencies. Polarization effects of beam splitters, reflectors, and their composite combinations (interferometers) are investigated in detail. General conditions for complete or restricted polarization compensation are derived. Theoretical SNR expressions for both the source beam and the detector beam are also obtained; these formulas specifically account for the incident state of polarization, the polarization effects of the interferometer, and make use of the exact expressions for the appropriate interferometer efficiency. In an Appendix, a brief comparison is made between some usual representations of the state of wave polarization.