  The Phase-Induced Amplitude Apodization (PIAA) coronagraph is a high
performance coronagraph concept able to work at small angular separation with
little loss in throughput. We present results obtained with a laboratory PIAA
system including active wavefront control. The system has a 94.3% throughput
(excluding coating losses) and operates in air with monochromatic light.
  Our testbed achieved a 2.27e-7 raw contrast between 1.65 lambda/D (inner
working angle of the coronagraph configuration tested) and 4.4 lambda/D (outer
working angle). Through careful calibration, we were able to separate this
residual light into a dynamic coherent component (turbulence, vibrations) at
4.5e-8 contrast and a static incoherent component (ghosts and/or polarization
missmatch) at 1.6e-7 contrast. Pointing errors are controlled at the 1e-3
lambda/D level using a dedicated low order wavefront sensor.
  While not sufficient for direct imaging of Earth-like planets from space, the
2.27e-7 raw contrast achieved already exceeds requirements for a ground-based
Extreme Adaptive Optics system aimed at direct detection of more massive
exoplanets. We show that over a 4hr long period, averaged wavefront errors have
been controlled to the 3.5e-9 contrast level. This result is particularly
encouraging for ground based Extreme-AO systems relying on long term stability
and absence of static wavefront errors to recover planets much fainter than the
fast boiling speckle halo.
