Low-nonlinearity advantage of hollow-core fiber for wavelength multiplexing of quantum entanglement and classical DWDM signals

Hikaru Shimizu; Arisa Ohno; Mao Miyasugi; Yumeno Seki; Naoyuki Funaoka; Yukari Takada; Aruto Hosaka; Shun Fujii; Hiroyuki Tsuda; Masahiro Takeoka

arXiv · 2610.27540

Low-nonlinearity advantage of hollow-core fiber for wavelength multiplexing of quantum entanglement and classical DWDM signals

Hikaru Shimizu·Arisa Ohno·Mao Miyasugi·Yumeno Seki·Naoyuki Funaoka·Yukari Takada·Aruto Hosaka·Shun Fujii·Hiroyuki Tsuda·Masahiro Takeoka

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Abstract

Coexistence of classical and quantum light in optical fiber is a key requirement for scalable quantum networks. However, it is fundamentally limited by nonlinear crosstalk from intense classical signals. Hollow-core fiber (HCF), with its intrinsically low optical nonlinearity, offers a promising solution. Here, we experimentally demonstrate the coexistence of polarization-entangled photons with dense wavelength-division multiplexed (DWDM) classical signals with a total launch power of 11.2 dBm, and perform a direct comparison between equal-length single-mode fiber (SMF) and photonic-bandgap-based HCF deployed in a campus network. We observe that HCF suppresses background noise by approximately two orders of magnitude compared to SMF, while preserving high-fidelity entanglement distribution. Our results provide clear experimental evidence of the advantage of HCF and establish its potential as a transmission medium.

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Hikaru Shimizu, Arisa Ohno, Mao Miyasugi, Yumeno Seki, Naoyuki Funaoka, Yukari Takada, Aruto Hosaka, Shun Fujii, Hiroyuki Tsuda, Masahiro Takeoka. 2026-10-20. Low-nonlinearity advantage of hollow-core fiber for wavelength multiplexing of quantum entanglement and classical DWDM signals. https://arxiv.org/abs/2610.27540

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