A precise atomic parity violation (APV) experiment provides an original test of the electron-nuclear weak interaction mediated by the neutral vector boson Z°, a test complementary to high energy experiments. It consists in measuring a left-right asymmetry of 10^-6 in the light-atom interaction, associated with a transition dipole E1pv of only 10^-13 ea0 in the highly forbidden 6S-7S transition of atomic cesium. Our pulsed pump-probe experiment, carried out in a vapor cell submitted to a longitudinal E-field, provides a novel method of APV measurement by exploiting the amplification of the asymmetryby stimulated emission. Since the first demonstration in 2002, decisive improvements have been implemented and and the latest runs performed in 2004 yield a 2.6% accurate determination of E1pv