  Indistinguishable photons play a key role in quantum optical information
technologies. We characterize the output of an ultra-bright photon-pair source
using multi-particle tomography [R. B. A. Adamson et al., Phys. Rev. Lett. 98,
043601 (2007)] and separately identify coherent errors, decoherence, and
distinguishability. We demonstrate generation of high-quality indistinguishable
pairs and polarization NOON states with 99% fidelity to an ideal NOON state.
Using a NOON state we perform a super-resolving angular measurement with 90%
visibility.
