Atom-Network Telecom Exchange

Wavelength conversion is a critical enabling subsystem for quantum networks. The proposed quantum wavelength convertor is a device for converting single-photons from wavelengths compatible with atom-based quantum networking systems to wavelengths for low-attenuation transmission in optical fiber. In conventional networks, these devices impart flexibility between optical channels and maximize the capacity of wavelength division multiplexed systems. In contrast, no commercial system exists to meet the needs of quantum networks in currently demonstrated hardware. Wavelength conversion provides crucial system-level functionality to both Quantum Local Area Networks, where they ensure system compatibility with the best available subsystem hardware, for example interfacing between erbium doped fiber amplifiers operating near 1500 nm and high quantum efficiency detectors operating near 800 nm; and Quantum Wide Area Networks, where wavelength conversion ensures use of optimal wavelengths for long-distance quantum information transfer. The Phase I effort will consist three sets of activities in parallel: system design, laboratory studies, and feasibility estimation of performance enhancement concepts. Phase I preparation of a complete system design, including vacuum cell, physics package, and control electronics, will set up rapid fabrication and testing progress in Phase II. Laboratory studies will leverage existing experimental infrastructure to investigate the achievable wavelength-conversion duty cycle using the proposed technology, an important practical performance metric for using wavelength-conversion to enable quantum network functionality. Finally, although the technology’s demonstrated single-photon wavelength conversion efficiency is already the best available, during Phase I the feasibility of concepts for further performance enhancement will be investigated. Completion of these activities will make delivery of a turn-key prototype wavelength-converter to collaborators in Phase II possible. The most direct approach to a practical quantum network is to fully leverage existing conventional optical network technology. Due to infrared absorption at longer wavelengths and Rayleigh scattering at shorter wavelengths, there is a sharp minimum of optical fiber attenuation at telecom wavelengths. Through completion of the proposed work, the single largest barrier to the use of conventional optical technology interfaced with atom-based quantum network components is eliminated by converting quantum network wavelengths to those compatible with conventional networks. This single technology will reduce the commercial cost of deploying a quantum network immeasurably. Simply looking at the cost of leveraging conventional optical fiber networks for the quantum transmission, the estimated cost per route mile is $100k and it is estimated that there are 113,000 miles of long-haul optical fiber in the US. If the proposed wavelength-converter were to enable the full use of these fibers for piggybacked quantum networks, the technology would enable a savings of over $11B over deploying a dedicated quantum fiber network, assuming that were even practical. Due to the enormity of cost savings, once demonstrated, this technology becomes critical to all such quantum networks and the significance of its commercial value makes the likelihood of it becoming a marketable product absolute. Furthermore, contacts within a DOE lab and in the wider telecom industry have already expressed interest in assisting with prototype demonstration, testing, and integration with existing optical fiber network infrastructure, which will help to shepherd the technology across the traditional funding “valley of death”.