  We present a scheme for realization of quantum mechanical weak values of
observables using entangled photons produced in parametric down conversion. We
consider the case when the signal and idler modes are respectively in a
coherent state and vacuum. We use a low efficiency detector to detect the
photons in the idler mode.This weak detection leads to a large displacement and
fluctuations in the signal field's quantum state which can be studied by
monitoring the photon number and quadrature distributions.
