High-purity, high-rate, photon pair source for space-based entanglement distribution

The overall goal of this NASA effort is to develop and deliver efficient, single-pass quantum optical waveguide sources generating high purity polarization entangled photon pairs for use in high-rate long-distance links. The key innovation in this effort is the use of efficient, low-loss spontaneous parametric down conversion (SPDC) waveguides in combination with apodized gratings to tailor the optical nonlinear response to create quantum optical states with very high purity. In addition, the photon pair generation rate for these devices is very high, while payload size, weight, and power (SWaP) are tiny. They offer a key technology required for deployment of space-to-ground links and future construction of a global quantum network.