Nonclassical Mueller polarimetry

Quantum correlations are non-classical features of quantum systems that can be harnessed in new technologies. Nonlocality, a unique byproduct of the entanglement of more than one particle, can alter the causal sequence that is present in a classical measurement. In this work, we investigate a nonlocal form of Mueller polarimetry. In the classical method, light prepared in an initial state passes through a sample whose polarization properties are unknown, and the light's modified polarization state is subsequently measured. From a series of measurements, the Mueller matrix is obtained, which contains the polarization properties of the sample. In the nonclassical version of the technique presented here, the initial and final parts of this measurement were split into polarization projections on two polarization-entangled photons, but linked through quantum correlations in the post-selection process. We found the results with samples of known and unknown Mueller matrix using this approach to be equivalent to the classical ones. The nonlocal feature of the measurement can invert the causal order of preparation and measurement in the classical method. We present a study of its limitations when the entangled state of the photons is not the ideal one. From this work, we conclude that the technique is very resilient to imperfections in the quantum state of the photons, making it a feasible alternative to the classical method.