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arXiv · 2304.10053

Two-mode squeezing over deployed fiber coexisting with conventional communications

Joseph C. Chapman·Alexander Miloshevsky·Hsuan-Hao Lu·Nageswara Rao·Muneer Alshowkan·Nicholas A. Peters
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Abstract

Squeezed light is a crucial resource for continuous-variable (CV) quantum information science. Distributed multi-mode squeezing is critical for enabling CV quantum networks and distributed quantum sensing. To date, multi-mode squeezing measured by homodyne detection has been limited to single-room experiments without coexisting classical signals, i.e., on ``dark'' fiber. Here, after distribution through separate fiber spools (5~km), $-0.9\pm0.1$-dB coexistent two-mode squeezing is measured. Moreover, after distribution through separate deployed campus fibers (about 250~m and 1.2~km), $-0.5\pm0.1$-dB coexistent two-mode squeezing is measured. Prior to distribution, the squeezed modes are each frequency multiplexed with several classical signals -- including the local oscillator and conventional network signals -- demonstrating that the squeezed modes do not need dedicated dark fiber. After distribution, joint two-mode squeezing is measured and recorded for post-processing using triggered homodyne detection in separate locations. This demonstration enables future applications in quantum networks and quantum sensing that rely on distributed multi-mode squeezing.

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Joseph C. Chapman, Alexander Miloshevsky, Hsuan-Hao Lu, Nageswara Rao, Muneer Alshowkan, Nicholas A. Peters. 2023-07-12. Two-mode squeezing over deployed fiber coexisting with conventional communications. https://doi.org/10.1364/oe.492539

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