  We propose a phase estimation protocol for optical interferometry that
employs a probe state (containing on average n photons) obtained by squeezing
each mode, separately, of a single photon path entangled Bell state. This
scheme involves a Mach-Zehnder type interferometer for which each mode is
squeezed after the first beam splitter. Information about the differential
phase is extracted using a parity detection and the resulting measurement
signal is super-resolving and supersensitive, with a minimum phase uncertainty
2/(n+1). This probe state can be generated with current technologies where n is
in the order of many thousands of photons.
