article published Maximilian Protte author 46170 Timon Schapeler author 556290000-0001-7652-1716 Jan Sperling author 751270000-0002-5844-3205 Tim Bartley author 49683 15 department 623 department PhoQuant: Photonische Quantencomputer - Quantencomputing Testplattform project ERC-Grant: QuESADILLA: Quantum Engineering Superconducting Array Detectors in Low-Light Applications project ISOQC: Quantenkommunikation mit integrierter Optik im Zusammenhang mit supraleitender Elektronik project <jats:p>Superconducting nanowire single-photon detectors (SNSPDs) have been widely used to study the discrete nature of quantum states of light in the form of photon-counting experiments. We show that SNSPDs can also be used to study continuous variables of optical quantum states by performing homodyne detection at a bandwidth of 400 kHz. By measuring the interference of a continuous-wave field of a local oscillator with the field of the vacuum state using two SNSPDs, we show that the variance of the difference in count rates is linearly proportional to the photon flux of the local oscillator over almost five orders of magnitude. The resulting shot-noise clearance of (46.0 ± 1.1) dB is the highest reported clearance for a balanced optical homodyne detector, demonstrating their potential for measuring highly squeezed states in the continuous-wave regime. In addition, we measured a CMRR = 22.4 dB. From the joint click counting statistics, we also measure the phase-dependent quadrature of a weak coherent state to demonstrate our device’s functionality as a homodyne detector.</jats:p> Optica Publishing Group2024 eng 2837-671410.1364/opticaq.502201 21 M. Protte, T. Schapeler, J. Sperling, and T. Bartley, “Low-noise balanced homodyne detection with superconducting nanowire single-photon detectors,” <i>Optica Quantum</i>, vol. 2, no. 1, Art. no. 1, 2024, doi: <a href="https://doi.org/10.1364/opticaq.502201">10.1364/opticaq.502201</a>. Protte, M., Schapeler, T., Sperling, J., &#38; Bartley, T. (2024). Low-noise balanced homodyne detection with superconducting nanowire single-photon detectors. <i>Optica Quantum</i>, <i>2</i>(1), Article 1. <a href="https://doi.org/10.1364/opticaq.502201">https://doi.org/10.1364/opticaq.502201</a> Protte, Maximilian, Timon Schapeler, Jan Sperling, and Tim Bartley. “Low-Noise Balanced Homodyne Detection with Superconducting Nanowire Single-Photon Detectors.” <i>Optica Quantum</i> 2, no. 1 (2024). <a href="https://doi.org/10.1364/opticaq.502201">https://doi.org/10.1364/opticaq.502201</a>. M. Protte, T. Schapeler, J. Sperling, T. Bartley, Optica Quantum 2 (2024). Protte, Maximilian, et al. “Low-Noise Balanced Homodyne Detection with Superconducting Nanowire Single-Photon Detectors.” <i>Optica Quantum</i>, vol. 2, no. 1, 1, Optica Publishing Group, 2024, doi:<a href="https://doi.org/10.1364/opticaq.502201">10.1364/opticaq.502201</a>. @article{Protte_Schapeler_Sperling_Bartley_2024, title={Low-noise balanced homodyne detection with superconducting nanowire single-photon detectors}, volume={2}, DOI={<a href="https://doi.org/10.1364/opticaq.502201">10.1364/opticaq.502201</a>}, number={11}, journal={Optica Quantum}, publisher={Optica Publishing Group}, author={Protte, Maximilian and Schapeler, Timon and Sperling, Jan and Bartley, Tim}, year={2024} } Protte M, Schapeler T, Sperling J, Bartley T. Low-noise balanced homodyne detection with superconducting nanowire single-photon detectors. <i>Optica Quantum</i>. 2024;2(1). doi:<a href="https://doi.org/10.1364/opticaq.502201">10.1364/opticaq.502201</a> 508402024-01-25T11:48:02Z2025-12-18T17:06:27Z