[{"abstract":[{"text":"Multimode squeezed light is an increasingly popular tool in photonic quantum technologies, including sensing, imaging, and computation. Meanwhile, the existing methods of its characterization are technically complicated, which reduces the level of squeezing, and mostly deal with a single mode at a time. Here, for the first time, to the best of our knowledge, we employ optical parametric amplification to characterize multiple squeezing eigenmodes simultaneously. We retrieve the shapes and squeezing degrees of all modes at once through direct detection followed by modal decomposition. This method is tolerant to inefficient detection and does not require a local oscillator. For a spectrally and spatially multimode squeezed vacuum, we characterize eight strongest spatial modes, obtaining squeezing and anti-squeezing values of up to −5.2 ± 0.2 dB and 8.6 ± 0.3 dB, respectively, despite the 50% detection loss. This work, being the first exploration of an optical parametric amplifier’s multimode capability for squeezing detection, paves the way for the real-time detection of multimode squeezing.","lang":"eng"}],"status":"public","type":"journal_article","publication":"Optica Quantum","article_number":"36","article_type":"original","language":[{"iso":"eng"}],"project":[{"_id":"53","name":"TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen"},{"name":"TRR 142 - Project Area C","_id":"56"},{"_id":"174","name":"TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse"},{"_id":"52","name":"Computing Resources Provided by the Paderborn Center for Parallel Computing"}],"_id":"63745","user_id":"55907","department":[{"_id":"15"},{"_id":"569"},{"_id":"170"},{"_id":"35"},{"_id":"429"}],"year":"2025","citation":{"mla":"Barakat, Ismail, et al. “Simultaneous Measurement of Multimode Squeezing through Multimode Phase-Sensitive Amplification.” <i>Optica Quantum</i>, vol. 3, no. 1, 36, Optica Publishing Group, 2025, doi:<a href=\"https://doi.org/10.1364/opticaq.524682\">10.1364/opticaq.524682</a>.","bibtex":"@article{Barakat_Kalash_Scharwald_Sharapova_Lindlein_Chekhova_2025, title={Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification}, volume={3}, DOI={<a href=\"https://doi.org/10.1364/opticaq.524682\">10.1364/opticaq.524682</a>}, number={136}, journal={Optica Quantum}, publisher={Optica Publishing Group}, author={Barakat, Ismail and Kalash, Mahmoud and Scharwald, Dennis and Sharapova, Polina and Lindlein, Norbert and Chekhova, Maria}, year={2025} }","short":"I. Barakat, M. Kalash, D. Scharwald, P. Sharapova, N. Lindlein, M. Chekhova, Optica Quantum 3 (2025).","apa":"Barakat, I., Kalash, M., Scharwald, D., Sharapova, P., Lindlein, N., &#38; Chekhova, M. (2025). Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification. <i>Optica Quantum</i>, <i>3</i>(1), Article 36. <a href=\"https://doi.org/10.1364/opticaq.524682\">https://doi.org/10.1364/opticaq.524682</a>","ama":"Barakat I, Kalash M, Scharwald D, Sharapova P, Lindlein N, Chekhova M. Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification. <i>Optica Quantum</i>. 2025;3(1). doi:<a href=\"https://doi.org/10.1364/opticaq.524682\">10.1364/opticaq.524682</a>","ieee":"I. Barakat, M. Kalash, D. Scharwald, P. Sharapova, N. Lindlein, and M. Chekhova, “Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification,” <i>Optica Quantum</i>, vol. 3, no. 1, Art. no. 36, 2025, doi: <a href=\"https://doi.org/10.1364/opticaq.524682\">10.1364/opticaq.524682</a>.","chicago":"Barakat, Ismail, Mahmoud Kalash, Dennis Scharwald, Polina Sharapova, Norbert Lindlein, and Maria Chekhova. “Simultaneous Measurement of Multimode Squeezing through Multimode Phase-Sensitive Amplification.” <i>Optica Quantum</i> 3, no. 1 (2025). <a href=\"https://doi.org/10.1364/opticaq.524682\">https://doi.org/10.1364/opticaq.524682</a>."},"intvolume":"         3","publication_status":"published","publication_identifier":{"issn":["2837-6714"]},"issue":"1","title":"Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification","main_file_link":[{"url":"https://opg.optica.org/opticaq/viewmedia.cfm?uri=opticaq-3-1-36&seq=0","open_access":"1"}],"doi":"10.1364/opticaq.524682","publisher":"Optica Publishing Group","oa":"1","date_updated":"2026-02-10T22:44:44Z","date_created":"2026-01-26T15:57:13Z","author":[{"full_name":"Barakat, Ismail","last_name":"Barakat","first_name":"Ismail"},{"first_name":"Mahmoud","last_name":"Kalash","full_name":"Kalash, Mahmoud"},{"first_name":"Dennis","full_name":"Scharwald, Dennis","id":"55907","last_name":"Scharwald","orcid":"0009-0007-5654-5412"},{"first_name":"Polina","last_name":"Sharapova","full_name":"Sharapova, Polina","id":"60286"},{"last_name":"Lindlein","full_name":"Lindlein, Norbert","first_name":"Norbert"},{"last_name":"Chekhova","full_name":"Chekhova, Maria","first_name":"Maria"}],"volume":3},{"type":"journal_article","publication":"Optica Quantum","status":"public","user_id":"63574","department":[{"_id":"288"},{"_id":"623"},{"_id":"288"}],"project":[{"_id":"211","name":"QuICHE: Quanteninformation und Quantenkommunikation mit hochdimensionaler Informationskodierung (QuICHE)"}],"_id":"56267","language":[{"iso":"eng"}],"publication_status":"published","publication_identifier":{"issn":["2837-6714"]},"citation":{"apa":"Serino, L., Ridder, W., Bhattacharjee, A., Gil López, J., Brecht, B., &#38; Silberhorn, C. (2024). Orchestrating time and color: a programmable source of high-dimensional entanglement. <i>Optica Quantum</i>. <a href=\"https://doi.org/10.1364/opticaq.532334\">https://doi.org/10.1364/opticaq.532334</a>","short":"L. Serino, W. Ridder, A. Bhattacharjee, J. Gil López, B. Brecht, C. Silberhorn, Optica Quantum (2024).","mla":"Serino, Laura, et al. “Orchestrating Time and Color: A Programmable Source of High-Dimensional Entanglement.” <i>Optica Quantum</i>, Optica Publishing Group, 2024, doi:<a href=\"https://doi.org/10.1364/opticaq.532334\">10.1364/opticaq.532334</a>.","bibtex":"@article{Serino_Ridder_Bhattacharjee_Gil López_Brecht_Silberhorn_2024, title={Orchestrating time and color: a programmable source of high-dimensional entanglement}, DOI={<a href=\"https://doi.org/10.1364/opticaq.532334\">10.1364/opticaq.532334</a>}, journal={Optica Quantum}, publisher={Optica Publishing Group}, author={Serino, Laura and Ridder, Werner and Bhattacharjee, Abhinandan and Gil López, Jano and Brecht, Benjamin and Silberhorn, Christine}, year={2024} }","chicago":"Serino, Laura, Werner Ridder, Abhinandan Bhattacharjee, Jano Gil López, Benjamin Brecht, and Christine Silberhorn. “Orchestrating Time and Color: A Programmable Source of High-Dimensional Entanglement.” <i>Optica Quantum</i>, 2024. <a href=\"https://doi.org/10.1364/opticaq.532334\">https://doi.org/10.1364/opticaq.532334</a>.","ieee":"L. Serino, W. Ridder, A. Bhattacharjee, J. Gil López, B. Brecht, and C. Silberhorn, “Orchestrating time and color: a programmable source of high-dimensional entanglement,” <i>Optica Quantum</i>, 2024, doi: <a href=\"https://doi.org/10.1364/opticaq.532334\">10.1364/opticaq.532334</a>.","ama":"Serino L, Ridder W, Bhattacharjee A, Gil López J, Brecht B, Silberhorn C. Orchestrating time and color: a programmable source of high-dimensional entanglement. <i>Optica Quantum</i>. Published online 2024. doi:<a href=\"https://doi.org/10.1364/opticaq.532334\">10.1364/opticaq.532334</a>"},"year":"2024","author":[{"last_name":"Serino","id":"88242","full_name":"Serino, Laura","first_name":"Laura"},{"full_name":"Ridder, Werner","id":"63574","last_name":"Ridder","first_name":"Werner"},{"full_name":"Bhattacharjee, Abhinandan","id":"95902","last_name":"Bhattacharjee","first_name":"Abhinandan"},{"full_name":"Gil López, Jano","id":"51223","last_name":"Gil López","first_name":"Jano"},{"id":"27150","full_name":"Brecht, Benjamin","orcid":"0000-0003-4140-0556 ","last_name":"Brecht","first_name":"Benjamin"},{"last_name":"Silberhorn","id":"26263","full_name":"Silberhorn, Christine","first_name":"Christine"}],"date_created":"2024-09-27T11:46:59Z","date_updated":"2025-12-01T08:49:46Z","publisher":"Optica Publishing Group","doi":"10.1364/opticaq.532334","title":"Orchestrating time and color: a programmable source of high-dimensional entanglement"},{"publication":"Optica Quantum","type":"journal_article","abstract":[{"text":"<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>","lang":"eng"}],"status":"public","_id":"50840","project":[{"name":"PhoQuant: Photonische Quantencomputer -  Quantencomputing Testplattform","_id":"191"},{"_id":"239","name":"ERC-Grant: QuESADILLA: Quantum Engineering Superconducting Array Detectors in Low-Light Applications"},{"_id":"209","name":"ISOQC: Quantenkommunikation mit integrierter Optik im Zusammenhang mit supraleitender Elektronik"}],"department":[{"_id":"15"},{"_id":"623"}],"user_id":"55629","article_number":"1","language":[{"iso":"eng"}],"publication_identifier":{"issn":["2837-6714"]},"publication_status":"published","issue":"1","year":"2024","intvolume":"         2","citation":{"ama":"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>","chicago":"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>.","ieee":"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>.","apa":"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>","bibtex":"@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} }","mla":"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>.","short":"M. Protte, T. Schapeler, J. Sperling, T. Bartley, Optica Quantum 2 (2024)."},"oa":"1","publisher":"Optica Publishing Group","date_updated":"2025-12-18T17:06:27Z","volume":2,"author":[{"last_name":"Protte","id":"46170","full_name":"Protte, Maximilian","first_name":"Maximilian"},{"first_name":"Timon","id":"55629","full_name":"Schapeler, Timon","last_name":"Schapeler","orcid":"0000-0001-7652-1716"},{"first_name":"Jan","full_name":"Sperling, Jan","id":"75127","orcid":"0000-0002-5844-3205","last_name":"Sperling"},{"last_name":"Bartley","id":"49683","full_name":"Bartley, Tim","first_name":"Tim"}],"date_created":"2024-01-25T11:48:02Z","title":"Low-noise balanced homodyne detection with superconducting nanowire single-photon detectors","doi":"10.1364/opticaq.502201","main_file_link":[{"open_access":"1"}]}]