  The quantum theoretical concepts of modular momentum and dynamical
non-locality, which were introduced four decades ago, have recently been used
to explain single particle quantum interference phenomena. Although the
non-local exchange of modular momentum associated with such phenomena cannot be
directly observed, it has been suggested that effects induced by this exchange
can be measured experimentally using weak measurements of pre- and
post-selected ensembles of particles. This paper reports on such an optical
experiment that yielded measured weak values that were consistent with the
theoretical prediction of an effect induced by a non-local exchange of modular
momentum.
