  A new criterion, based on noncontextuality, is derived to discriminate
between separable and nonseparable states in classical wave optics where no
discreteness is involved. An experiment is proposed to test the violation of
noncontextuality by a nonseparable state. Such states have only recently begun
to be explored. The significance of their nonseparability or entanglement as
well as their similarities with and differences from entangled quantum states
are discussed.
