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arXiv · 1803.07749

Ultrabright narrow-band telecom two-photon source for long-distance quantum communication

Kazuya Niizeki·Kohei Ikeda·Mingyang Zheng·Xiuping Xie·Kotaro Okamura·Nobuyuki Takei·Naoto Namekata·Shuichiro Inoue·Hideo Kosaka·Tomoyuki Horikiri
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Abstract

We demonstrate an ultrabright narrow-band two-photon source at the 1.5 -μm telecom wavelength for long-distance quantum communication. By utilizing a bow-tie cavity, we obtain a cavity enhancement factor of $4.06\times 10^4$. Our measurement of the second-order correlation function $G^{(2)} (τ)$ reveals that the linewidth of $2.4$ MHz has been hitherto unachieved in the 1.5 -μm telecom band. This two-photon source is useful for obtaining a high absorption probability close to unity by quantum memories set inside quantum repeater nodes. Furthermore, to the best of our knowledge, the observed spectral brightness of $3.94\times 10^5$ pairs/(s$\cdot$MHz$\cdot$mW) is also the highest reported over all wavelengths.

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Kazuya Niizeki, Kohei Ikeda, Mingyang Zheng, Xiuping Xie, Kotaro Okamura, Nobuyuki Takei, Naoto Namekata, Shuichiro Inoue, Hideo Kosaka, Tomoyuki Horikiri. 2018-03-21. Ultrabright narrow-band telecom two-photon source for long-distance quantum communication. https://doi.org/10.7567/apex.11.042801

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