Quantum decoherence versus classical depolarization in nanohole arrays

We present a theoretical model of the quantum decoherence experienced by a pair of polarization-entangled photons, after one of them is sent through a nanohole array, and compare this with the classical depolarization experienced by light with a fixed polarization when this is sent through the same array. We discuss the conditions under which the quantum visibility and the classical degree of polarization are the same. Experimental verification is done with arrays of square and hexagonal symmetry.