Efficient Narrowband Entangled Photon Sources for Interfacing with Quantum Memory

Scalable, long-distance quantum networking will require quantum repeaters, and quantum memories are an essential component of scalable quantum repeaters. This Phase I STTR will work to develop a photon pair source with sufficiently narrow photon pair generation enabling efficient interfacing to a Silicon vacancy (SiV) center quantum memory. The bandwidths of the downconverted photons are much broader (> 100GHz) than required for efficient interfacing to quantum memories (< 1GHz). SPDC photon spectra can be efficiently narrowed by cavity enhancement. We propose the development of a commercial source of cavity enhanced SPDC using a monolithic waveguide chip as the cavity itself. This combines the benefits of waveguide-based SPDC and cavity-enhancement without the need for external optics, resulting in stable and efficient operation.