Signal and noise analysis of non-modulated polarimeters using Mueller calculus simulations

Abstract

Two non-modulated polarimeters have been modelled using the Mueller optical calculus. The effects of polarizer extinction ratio, orientation of the polarizer, source shot noise, 1/f noise and polarization ratio, on the signal-to-noise ratio of the measurement of optical activity, are evaluated. It is shown that the performance of a conventional polarimeter consisting of a crossed polarizer pair is strongly influenced by the arrangement of the optics and the type of dominant noise. The quality of the optics used is also important, if the measurement is source 1/f noise limited. The other polarimeter modelled, consists of a polarizer in combination with a polarizing prism, which resolves the light into orthogonally polarized components. Numerical simulation of this design shows that its performance is not degraded by the use of inferior optics, provided that the optics are positioned appropriately. The optimum arrangement is influenced by the dominant noise type, and in some instances, the polarization ratio and the quality of the optical components. However, the optimum arrangement may prove difficult to achieve experimentally. This design is also shown to be superior to the other scheme because of its ability to discriminate against source noise effectively.