Generalized framework of weak-value amplification in path interference of polarized light for the enhancement of all possible polarization anisotropy effects

Abstract

Using the profound interferometric philosophy of weak-value amplification, we propose a simple, general, and robust polarization method for the amplification and quantification of small magnitudes of all possible polarization anisotropy effects in a single experimental embodiment. The approach is experimentally realized by introducing a weak coupling between the polarization degree of freedom of light and the path degree of freedom in a Mach-Zehnder interferometer in the presence of a weak anisotropy effect. Real and imaginary weak-value amplifications of different polarization anisotropy effects are manifested as characteristic changes in the relevant Stokes vector elements at the exit port of the interferometer, which follow orthogonal trajectories in the Poincaré sphere. The proof-of-concept experiment demonstrates that by using this scheme, one can faithfully extract and quantify an anisotropy parameter that is smaller than the typical sensitivity of measurement of a given Stokes parameter of a traditional polarimeter by a large weak-value amplification factor. This opens up the possibility of a sample measuring weak-value polarimeter for studying the rich variety of fundamental optical effects and for materials characterization and precision metrology.