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arXiv · 2606.27911

Quantum frequency comb with pump-selectable bin pairing and extraction-aware loading in a lithium niobate microresonator

Mohamad Reza Nurrahman·Hyeon Hwang·Nuri Han·Guhwan Kim·Hong-Seok Kim·Kiwon Moon·Jung Jin Ju·Hansuek Lee·Min-Kyo Seo
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Abstract

Integrated quantum photonics requires bright, high-fidelity photon-pair sources capable of spectral multiplexing, correlation control, and circuit-compatible extraction. Cavity-enhanced spontaneous parametric down-conversion (SPDC) increases pair generation, but triply resonant operation imposes stringent pump-signal-idler spectral-alignment constraints. Moreover, the trade-off between intrinsic generation and coincidence-to-accidental ratio (CAR) does not capture the usable output flux, which depends on photon extraction. Here, we demonstrate a single-pass-pumped, resonator-enhanced quantum frequency comb (QFC) source based on a periodically poled lithium niobate photonic-crystal Fabry-P$é$rot microresonator. The device yields intrinsic and loaded brightnesses of 69.9 and 1.88 MHz/$μ$W, respectively, and a maximum CAR of 16,000. Frequency-resolved measurements reveal 461 cavity-defined bins spanning 1495-1570 nm, and loaded spectral brightness approaching $4.29\times10^9$ pairs/(s$\cdot$mW$\cdot$nm). Heralded autocorrelation measurements yield a second-order autocorrelation $g_H^{(2)}(0)$ as low as $4.0\times10^{-4}$ for a selected high-CAR cavity-defined bin pair. In particular, tuning the single-pass pump deterministically selects correlated frequency-bin pairings within the fixed QFC grid while preserving brightness and pairwise coincidence rates. We further separate intrinsic generation from output photon-pair flux, revealing the loaded-brightness-CAR relation. Together, pump-selectable bin pairing and extraction-aware loading point to tailored SPDC QFCs as chip-integrated nonclassical light resources for multichannel quantum-state transport and information processing.

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Mohamad Reza Nurrahman, Hyeon Hwang, Nuri Han, Guhwan Kim, Hong-Seok Kim, Kiwon Moon, Jung Jin Ju, Hansuek Lee, Min-Kyo Seo. 2026-07-22. Quantum frequency comb with pump-selectable bin pairing and extraction-aware loading in a lithium niobate microresonator. https://arxiv.org/abs/2606.27911

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