Engineering an ideal indistinguishable photon-pair source for optical quantum information processing

The eventual success of optical quantum information (QI) processing depends critically on the available technologies. Photons produced via the nonlinear process of spontaneous parametric downconversion (SPDC) have now been used in a vast array of experiments in optical quantum computing and long-distance quantum communication. However, almost no source to date has been fully optimized. Here, we describe our progress in engineering an ideal photon-pair source for optical quantum information processing - polarization-entangled photons made indistinguishable by engineering spatio-spectral unentanglement at the source. We present solutions for several key challenges encountered in the development of the indistinguishable source. We expect such a source to directly translate into significantly enhanced QI protocols with higher rates, fidelities and efficiencies.