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arXiv · 2412.11371

Wavelength-Tunable and High-Heralding-Efficiency Quantum Photon Source in Birefringent Phase-Matched Lithium Niobate Waveguide

Zhu-Qi Tao·Xiao-Xu Fang·He Lu
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Abstract

Lithium niobate~(LN) is a birefringent material, where the strong birefringence thermo-optic effect is promising for the generation of quantum photon source with widely tunable wavelength. Here, we demonstrate birefringent phase-matching in a 20-mm-long waveguide fabricated on 5~$\mu$m-thick x-cut lithium niobate on insulator. The waveguide is deviated from the optical axis of LN by an angle of 53.5$^\circ$, enabling the phase matching between telecom and visible wavelengths. The phase-matching wavelength of this device can be thermally tuned with rate of 0.617~nm/K. We demonstrate the type-1 spontaneous parametric down-conversion to generate photon pairs with brightness of 2.2~MHz/mW and coincidence-to-accidental ratio up to $2.8\times10^5$. Furthermore, the heralded single photon is obtained from the photon pair with efficiency of 13.8\% and count rate up to 37.8~kHz.

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Zhu-Qi Tao, Xiao-Xu Fang, He Lu. 2024-12-16. Wavelength-Tunable and High-Heralding-Efficiency Quantum Photon Source in Birefringent Phase-Matched Lithium Niobate Waveguide. https://arxiv.org/abs/2412.11371

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