article published Denis A. Kopylov author Michael Stefszky author 42777 Torsten Meier author 3440000-0001-8864-2072 Christine Silberhorn author 26263 Polina R. Sharapova author 60286 15 department 569 department 170 department 293 department 288 department 230 department 623 department 429 department 35 department PhoQC: Photonisches Quantencomputing project TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen project TRR 142 - Project Area C project TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse project <jats:p>In this paper, we theoretically study the spectral and temporal properties of pulsed spontaneous parametric down-conversion (SPDC) generated in lossy waveguides. Our theoretical approach is based on the formalism of Gaussian states and the Langevin equation, which is elaborated for weak parametric down-conversion and photon-number-unresolved click detection. Using the example of frequency-degenerate type-II SPDC generated under the pump-idler group-velocity-matching condition, we show how the joint-spectral intensity, mode structure, normalized second-order correlation function, and Hong-Ou-Mandel interference pattern depend on internal losses of the SPDC process. We found that the joint-spectral intensity is almost insensitive to internal losses, while the second-order correlation function shows a strong dependence on them, being different for the signal and idler beams in the presence of internal losses. Based on the sensitivity of the normalized second-order correlation function, we show how its measurement can be used to experimentally determine internal losses.</jats:p> American Physical Society (APS)2025 eng 2643-156410.1103/zp72-7qwl 73 Kopylov, D. A., Stefszky, M., Meier, T., Silberhorn, C., &#38; Sharapova, P. R. (2025). Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation. <i>Physical Review Research</i>, <i>7</i>(3), Article 033122. <a href="https://doi.org/10.1103/zp72-7qwl">https://doi.org/10.1103/zp72-7qwl</a> D.A. Kopylov, M. Stefszky, T. Meier, C. Silberhorn, P.R. Sharapova, Physical Review Research 7 (2025). @article{Kopylov_Stefszky_Meier_Silberhorn_Sharapova_2025, title={Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation}, volume={7}, DOI={<a href="https://doi.org/10.1103/zp72-7qwl">10.1103/zp72-7qwl</a>}, number={3033122}, journal={Physical Review Research}, publisher={American Physical Society (APS)}, author={Kopylov, Denis A. and Stefszky, Michael and Meier, Torsten and Silberhorn, Christine and Sharapova, Polina R.}, year={2025} } Kopylov, Denis A., et al. “Spectral and Temporal Properties of Type-II Parametric down-Conversion: The Impact of Losses during State Generation.” <i>Physical Review Research</i>, vol. 7, no. 3, 033122, American Physical Society (APS), 2025, doi:<a href="https://doi.org/10.1103/zp72-7qwl">10.1103/zp72-7qwl</a>. Kopylov, Denis A., Michael Stefszky, Torsten Meier, Christine Silberhorn, and Polina R. Sharapova. “Spectral and Temporal Properties of Type-II Parametric down-Conversion: The Impact of Losses during State Generation.” <i>Physical Review Research</i> 7, no. 3 (2025). <a href="https://doi.org/10.1103/zp72-7qwl">https://doi.org/10.1103/zp72-7qwl</a>. D. A. Kopylov, M. Stefszky, T. Meier, C. Silberhorn, and P. R. Sharapova, “Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation,” <i>Physical Review Research</i>, vol. 7, no. 3, Art. no. 033122, 2025, doi: <a href="https://doi.org/10.1103/zp72-7qwl">10.1103/zp72-7qwl</a>. Kopylov DA, Stefszky M, Meier T, Silberhorn C, Sharapova PR. Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation. <i>Physical Review Research</i>. 2025;7(3). doi:<a href="https://doi.org/10.1103/zp72-7qwl">10.1103/zp72-7qwl</a> 629112025-12-05T09:33:36Z2025-12-05T09:55:22Z