Equivalence between optimum Young's fringe visibility and position-independent stochastic behavior of electromagnetic fields.

Stochastic electromagnetic fields characterized by optimized fringe visibility in a Young interferometric arrangement are shown to be those whose random character is position independent. The optimization procedure involves local unitary transformations, which can be implemented by using reversible anisotropic polarization devices placed at the two pinholes. It is also shown that the local degree of polarization in the optimized interferometer is constant across the superposition region and coincides with the degree of polarization at the two pinholes.