  A method for performing nonlocal interferometry using phase-entangled
macroscopic coherent states is described. The required entanglement can be
generated using weak nonlinearities while Bell's inequality can be violated
using single photons as a probe. The entanglement is relatively robust against
photon loss and Bell's inequality can be violated over a relatively large
distance in optical fibers despite the fact that a large number of photons are
absorbed in the process.
