Functions like data format conversion and signal routing are ubiquitous in traditional communication networks, but need modification to be suitable for use in future quantum-enabled networks. In particular, quantum signals do not allow for electronic processing and certain metrics like insertion loss and noise are much more critical for quantum signals than traditional optical signals. We will investigate all-optical, low-loss and low-noise tools suitable for achieving these functions in quantum networks. Our effort will make use of nonlinear effects to perform quantum frequency conversion and simultaneously modify the signal format and/or perform switching operations. To accomplish this task we will investigate the design and use of specialized nonlinear crystals that make use of engineered quasi-phase matching techniques. We will furthermore investigate means of dynamically controlling the nonlinear interaction to allow for high level signal manipulation such as routing. The systems and devices being explored have direct application for controlling signals in a quantum network. Such networks can enhance functions such as distributed sensing and quantum computation beyond what would be possible classically. The technology may have other applications such as in secure communications, atmospheric science, or classical optical sensor networks.
