Tunable phase-coherent FWM for quantum wavelength interconnects

Abstract

Quantum frequency conversion (QFC) plays a pivotal role in enabling coherent photonic interfaces across disparate quantum systems, serving as a foundation for scalable and interoperable quantum networks. Among various approaches, four-wave mixing (FWM) offers a promising path toward efficient, broadband QFC. In this work, we investigate the feasibility of phase-preserving frequency conversion, a necessary condition for coherent quantum state transfer, by characterizing the spectral phase mapping from input to output fields. We model nonlinear propagation through a gas-filled hollow-core capillary fiber, to demonstrate highly phase-coherent frequency conversion across a broad spectral range, including the infrared to ultraviolet, such as telecom (1550 nm) to visible (516 nm) and deep-UV (308 nm). We further examine how phase-mapping quality and conversion efficiency depend on key system parameters, including the intermediate pulse bandwidth and input pulse energy. Our results reveal optimal operating conditions for achieving future efficient and coherent QFC and provide valuable insights into the nonlinear dynamics underlying FWM-based transduction. These findings lay the groundwork for integrating heterogeneous quantum platforms across widely separated optical bands.