Nonlinear Optics for Quantum Frequency Conversion | NIST

Yu A Il'inskiĭ, Vera M. Petnikova

Shoichi Murakami, Shunsuke Hiraoka, Toshiki Kobayashi +2 more

We demonstrate channel-selective frequency up-conversion from telecom wavelengths around 1540 nm for optical fiber communication to visible wavelengths around 780 nm, based on second-order optical nonlinearity in a cavity of the converted modes. In our experiment, we selectively convert a light from any frequency mode within frequency-multiplexed telecom signals to a desired output mode, determined by the cavity resonances. Based on the experimental results of the frequency up-conversion, we derive the signal-to-noise ratio of the process at the single-photon level, and discuss its applicability to channel-selective quantum frequency conversion (CS-QFC) in the context of frequency-multiplexed quantum networks. Finally, we describe specific use cases of the CS-QFC, which show its utility as a reconfigurable switching element in frequency-multiplexed networks, particularly for selectively performing Bell-state measurements between two photons originating from different frequencies.

Nathan R. Newbury, Esther Baumann, Ian R. Coddington +2 more

Chin-Yao Cheng, Jia-Juan Lee, Ziyu Liu +2 more

Quantum frequency conversion (QFC), a critical technology in photonic quantum information science, requires that the quantum characteristics of the frequency-converted photon must be the same as the input photon except for the color. In nonlinear optics, the wave mixing effect far away from the resonance condition is often used to realize QFC because it can prevent the vacuum field reservoir from destroying the quantum state of the converted photon effectively. Under conditions far away from resonance, experiments typically require strong pump light to generate large nonlinear interactions to achieve high-efficiency QFC. However, strong pump light often generates additional noise photons through spontaneous Raman or parametric conversion processes. Herein, we theoretically study another efficient QFC scheme based on a resonant four-wave mixing system. Due to the effect of electromagnetically induced transparency (EIT), this resonant QFC scheme can greatly suppress vacuum field noise at low light levels; consequently, the converted photon can inherit the quantum state of the input photon with high fidelity. Our research demonstrates that if the conversion efficiency of the EIT-based QFC is close to 100%, the wave function and quadrature variance of the converted photon are almost the same as the input probe photon.

Prem Kumar, Paul G. Kwiat, Alan L. Migdall +3 more

Hao Zhang, Yang Xu, Linshan Sun +3 more

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.