arXiv subjects

Hideki Shimoi

Publications and source records attributed to Hideki Shimoi.

4 recordsLinked to original sources

arXiv2026

A quantum frequency conversion hub interfacing with DWDM networks

Interconnecting heterogeneous quantum systems is an important step toward realizing the quantum internet. We propose a quantum network hub that interfaces local quantum devices with dense wavelength-division multiplexing (DWDM) networks in the telecom band via quantum frequency conversion (QFC) with frequency-channel selectivity. We show that standard periodically poled lithium niobate waveguides used for QFC exhibit a dispersion sweet spot, for example around the 780 nm band, enabling wide tunability of the pump wavelength while maintaining phase matching. Experimentally, we demonstrate the network hub by implementing a channel-selective and polarization-insensitive QFC from 780 nm to telecom wavelengths around 1540 nm. We achieve a pump tuning range of 2 THz and successfully distribute polarization-encoded single photons into 16 frequency channels on the ITU-T DWDM grid with 25 GHz channel spacing, while preserving the quantum information. These results position the QFC-based hub as a versatile backbone for connecting a wide range of quantum devices, spanning both photonic and matter-based systems, across frequency-multiplexed telecom networks.

quant-ph↗

arXiv2025

Waveguide-array-based multiplexed photonic interface for atom array

The growing demand for high-capacity quantum communication and large-scale quantum computing underscores the importance of networking quantum processing units via multiplexed photonic channels. A neutral atom array with multiplexed atom-photon entanglement is a promising platform for its realization. Here, we demonstrate a key multiplexed photonic interface guiding the photons from an atom array to a single-mode waveguide array fabricated on a glass-based photonic integrated circuit. Remarkable 10 channels out of the 32-channel waveguide array with 25 $\mu$m pitch couple to photons from 10 sites of the atom array with Rydberg gate-enabled separation. Based on the observed correlation between the atomic states and the polarization of the photon with a visibility of 0.87, we anticipate its applicability to a large-scale multiplexed atom-photon entanglement generation for networking quantum processing units.

quant-ph↗

arXiv2024

1xN DWDM channel selective quantum frequency conversion

Dense Wavelength Division Multiplexing (DWDM) is a key technology for realizing high-capacity and flexible quantum communication networks. In addition, to realize the emerging quantum internet, quantum frequency conversion is also essential for bridging different quantum systems over optical fiber networks. In this work, we demonstrate a channel-selective quantum frequency conversion (CS-QFC), which allows active selection of the frequency of the converted photon from multiple DWDM channels. The 2.5 THz bandwidth of our CS-QFC system shows the ability to establish a 100-ch DWDM dynamic link from a single quantum system. It promises to increase the diversity of the quantum network.

quant-ph↗

arXiv2024

Low-noise quantum frequency conversion with cavity enhancement of converted mode

Quantum frequency conversion (QFC) which converts the frequencies of photons while preserving the quantum state is an essential technology for realizing the quantum internet and quantum interconnect. For the QFC based on the frequency downconversion from visible to the telecom wavelengths around 1500 nm, it is widely known that noise photons produced by the strong pump light used for QFC contaminate the frequency-converted photon, which degrades the quality of the quantum property of the photon after QFC. In conventional QFC experiments, noise photons are removed using external narrowband frequency filter systems. In contrast, in this study, we implement a compact QFC device integrating the cavity structure only for the converted mode. While the cavity structure can enhance not only the desired QFC efficiency but also the noise photon generation rate, we show that the cavity-enhanced QFC followed by a relatively wide bandpass filter achieves the signal-to-noise ratio comparable to the QFCs with external narrowband filters. We experimentally demonstrate the cavity-enhanced QFC using a single photon at 780 nm to 1540 nm, in which the non-classical photon statistics is clearly observed after QFC.

quant-ph↗