  Using ultrafast photonic first-order differentiator applied on a partially
coherent field, we report the generation of two correlated temporal waveforms
and study their correlation properties upon linear and nonlinear propagation
along the two orthogonal polarization axis of a dispersive optical fiber.
Temporal correlations are maintained in linear propagation whereas Kerr
nonlinearity generates anti-correlated temporal intensity patterns for both
partially and uncorrelated fields. Experiments are in close agreement with the
theoretical analysis.
