  Phase distortions, or aberrations, can negatively influence the performance
of an optical imaging system. Through the use of position-momentum entangled
photons, we nonlocally correct for aberrations in one photon's optical path by
intentionally introducing the complementary aberrations in the optical path of
the other photon. In particular, we demonstrate the simultaneous nonlocal
cancellation of aberrations that are of both even and odd order in the photons'
transverse degrees of freedom. We also demonstrate a potential application of
this technique by nonlocally cancelling the effect of defocus in a quantum
imaging experiment and thereby recover the original spatial resolution.
