  We improve the precision of the interferometric weak-value-based beam
deflection measurement by introducing a power recycling mirror, creating a
resonant cavity. This results in \emph{all} the light exiting to the detector
with a large deflection, thus eliminating the inefficiency of the rare
postselection. The signal-to-noise ratio of the deflection is itself magnified
by the weak value. We discuss ways to realize this proposal, using a transverse
beam filter and different cavity designs.
