article published Nina Amelie Lange author 568430000-0001-6624-7098 Sebastian Lengeling author 44373 Philipp Mues author 497720000-0003-0643-7636 Viktor Quiring author Werner Ridder author 63574 Christof Eigner author 13244https://orcid.org/0000-0002-5693-3083 Harald Herrmann author 216 Christine Silberhorn author 26263 Tim Bartley author 49683 15 department 623 department 288 department TRR 142; TP C07: Hohlraum-verstärkte Parametrische Fluoreszenz mit zeitlicher Filterung unter Verwendung integrierter supraleitender Detektoren project The titanium in-diffused lithium niobate waveguide platform is well-established for reliable prototyping and packaging of many quantum photonic components at room temperature. Nevertheless, compatibility with certain quantum light sources and superconducting detectors requires operation under cryogenic conditions. We characterize alterations in phase-matching and mode guiding of a non-degenerate spontaneous parametric down-conversion process emitting around 1556 nm and 950 nm, under cryogenic conditions. Despite the effects of pyroelectricity and photorefraction, the spectral properties match our theoretical model. Nevertheless, these effects cause small but significant variations within and between cooling cycles. These measurements provide a first benchmark against which other nonlinear photonic integration platforms, such as thin-film lithium niobate, can be compared. Optica Publishing Group2025 eng 1094-408710.1364/oe.578108 3324 N. A. Lange <i>et al.</i>, “Widely non-degenerate nonlinear frequency conversion in cryogenic titanium in-diffused lithium niobate waveguides,” <i>Optics Express</i>, vol. 33, no. 24, Art. no. 50451, 2025, doi: <a href="https://doi.org/10.1364/oe.578108">10.1364/oe.578108</a>. Lange, N. A., Lengeling, S., Mues, P., Quiring, V., Ridder, W., Eigner, C., Herrmann, H., Silberhorn, C., &#38; Bartley, T. (2025). Widely non-degenerate nonlinear frequency conversion in cryogenic titanium in-diffused lithium niobate waveguides. <i>Optics Express</i>, <i>33</i>(24), Article 50451. <a href="https://doi.org/10.1364/oe.578108">https://doi.org/10.1364/oe.578108</a> N.A. Lange, S. Lengeling, P. Mues, V. Quiring, W. Ridder, C. Eigner, H. Herrmann, C. Silberhorn, T. Bartley, Optics Express 33 (2025). Lange, Nina Amelie, Sebastian Lengeling, Philipp Mues, Viktor Quiring, Werner Ridder, Christof Eigner, Harald Herrmann, Christine Silberhorn, and Tim Bartley. “Widely Non-Degenerate Nonlinear Frequency Conversion in Cryogenic Titanium in-Diffused Lithium Niobate Waveguides.” <i>Optics Express</i> 33, no. 24 (2025). <a href="https://doi.org/10.1364/oe.578108">https://doi.org/10.1364/oe.578108</a>. Lange, Nina Amelie, et al. “Widely Non-Degenerate Nonlinear Frequency Conversion in Cryogenic Titanium in-Diffused Lithium Niobate Waveguides.” <i>Optics Express</i>, vol. 33, no. 24, 50451, Optica Publishing Group, 2025, doi:<a href="https://doi.org/10.1364/oe.578108">10.1364/oe.578108</a>. @article{Lange_Lengeling_Mues_Quiring_Ridder_Eigner_Herrmann_Silberhorn_Bartley_2025, title={Widely non-degenerate nonlinear frequency conversion in cryogenic titanium in-diffused lithium niobate waveguides}, volume={33}, DOI={<a href="https://doi.org/10.1364/oe.578108">10.1364/oe.578108</a>}, number={2450451}, journal={Optics Express}, publisher={Optica Publishing Group}, author={Lange, Nina Amelie and Lengeling, Sebastian and Mues, Philipp and Quiring, Viktor and Ridder, Werner and Eigner, Christof and Herrmann, Harald and Silberhorn, Christine and Bartley, Tim}, year={2025} } Lange NA, Lengeling S, Mues P, et al. Widely non-degenerate nonlinear frequency conversion in cryogenic titanium in-diffused lithium niobate waveguides. <i>Optics Express</i>. 2025;33(24). doi:<a href="https://doi.org/10.1364/oe.578108">10.1364/oe.578108</a> 622692025-11-20T10:35:35Z2025-12-12T12:13:45Z