Correlation Metric for Polarization Changes

In this letter, we present a scalar metric for the "closeness", or correlation between two separate polarization rotation matrices. The metric is derived both in the Jones and Stokes-Mueller representation for polarization changes, and a relation between the correlation in the two descriptions is established. We have previously used this method for quantifying the correlations between parallel cores in multi-core fibers and use it here to experimentally quantify temporal polarization changes for a fiber subjected to surrounding temperature changes