[{"volume":4,"article_number":"593","issue":"3","publication":"Optics Continuum","type":"journal_article","user_id":"216","title":"SPDC single-photon source in Ti-indiffused diced ridge LiNbO<sub>3</sub> waveguides","abstract":[{"lang":"eng","text":"<jats:p>Stable and bright single photon sources are key components for future quantum applications. A simple fabrication method is an important requirement for such sources. Here, we present a single photon source based on diced ridge waveguides in titanium indiffused LiNbO<jats:sub>3</jats:sub>. These waveguides can be easily fabricated by combining planar titanium in-diffusion without lithographic patterning and easy-to-handle precision dicing. Such devices have the potential to generate high single photon rates because ridge structures are typically less prone to the photorefractive effect. We achieve waveguide propagation losses &lt;0.4dBcm and a SHG conversion efficiency of about 81%Wcm<jats:sup>2</jats:sup>. Harnessing a type-0 SPDC process to generate 1550 nm photons, we obtain a SPDC brightness of 3⋅10<jats:sup>5</jats:sup>1s⋅mW⋅nm, with a heralding efficiency of <jats:italic>η</jats:italic><jats:sub>h</jats:sub>=45% (<jats:italic>η</jats:italic><jats:sub>h,wg</jats:sub>=77.5% for the waveguide itself excluded setup losses) and a heralded second-order correlation function of <jats:italic>g</jats:italic><jats:sub>h</jats:sub><jats:sup>2</jats:sup>(0)&lt;0.003 at low pump powers.</jats:p>"}],"doi":"10.1364/optcon.557439","_id":"59069","date_updated":"2025-03-19T16:03:25Z","date_created":"2025-03-19T10:56:04Z","publisher":"Optica Publishing Group","year":"2025","publication_identifier":{"issn":["2770-0208"]},"language":[{"iso":"eng"}],"status":"public","citation":{"apa":"Kießler, C., Kirsch, M., Lengeling, S., Herrmann, H., &#38; Silberhorn, C. (2025). SPDC single-photon source in Ti-indiffused diced ridge LiNbO<sub>3</sub> waveguides. <i>Optics Continuum</i>, <i>4</i>(3), Article 593. <a href=\"https://doi.org/10.1364/optcon.557439\">https://doi.org/10.1364/optcon.557439</a>","ama":"Kießler C, Kirsch M, Lengeling S, Herrmann H, Silberhorn C. SPDC single-photon source in Ti-indiffused diced ridge LiNbO<sub>3</sub> waveguides. <i>Optics Continuum</i>. 2025;4(3). doi:<a href=\"https://doi.org/10.1364/optcon.557439\">10.1364/optcon.557439</a>","chicago":"Kießler, Christian, Michelle Kirsch, Sebastian Lengeling, Harald Herrmann, and Christine Silberhorn. “SPDC Single-Photon Source in Ti-Indiffused Diced Ridge LiNbO<sub>3</sub> Waveguides.” <i>Optics Continuum</i> 4, no. 3 (2025). <a href=\"https://doi.org/10.1364/optcon.557439\">https://doi.org/10.1364/optcon.557439</a>.","ieee":"C. Kießler, M. Kirsch, S. Lengeling, H. Herrmann, and C. Silberhorn, “SPDC single-photon source in Ti-indiffused diced ridge LiNbO<sub>3</sub> waveguides,” <i>Optics Continuum</i>, vol. 4, no. 3, Art. no. 593, 2025, doi: <a href=\"https://doi.org/10.1364/optcon.557439\">10.1364/optcon.557439</a>.","mla":"Kießler, Christian, et al. “SPDC Single-Photon Source in Ti-Indiffused Diced Ridge LiNbO<sub>3</sub> Waveguides.” <i>Optics Continuum</i>, vol. 4, no. 3, 593, Optica Publishing Group, 2025, doi:<a href=\"https://doi.org/10.1364/optcon.557439\">10.1364/optcon.557439</a>.","bibtex":"@article{Kießler_Kirsch_Lengeling_Herrmann_Silberhorn_2025, title={SPDC single-photon source in Ti-indiffused diced ridge LiNbO<sub>3</sub> waveguides}, volume={4}, DOI={<a href=\"https://doi.org/10.1364/optcon.557439\">10.1364/optcon.557439</a>}, number={3593}, journal={Optics Continuum}, publisher={Optica Publishing Group}, author={Kießler, Christian and Kirsch, Michelle and Lengeling, Sebastian and Herrmann, Harald and Silberhorn, Christine}, year={2025} }","short":"C. Kießler, M. Kirsch, S. Lengeling, H. Herrmann, C. Silberhorn, Optics Continuum 4 (2025)."},"publication_status":"published","department":[{"_id":"15"},{"_id":"623"},{"_id":"288"}],"article_type":"original","author":[{"id":"44252","last_name":"Kießler","full_name":"Kießler, Christian","first_name":"Christian"},{"first_name":"Michelle","full_name":"Kirsch, Michelle","last_name":"Kirsch","id":"69553"},{"first_name":"Sebastian","full_name":"Lengeling, Sebastian","last_name":"Lengeling","id":"44373"},{"id":"216","last_name":"Herrmann","first_name":"Harald","full_name":"Herrmann, Harald"},{"full_name":"Silberhorn, Christine","first_name":"Christine","id":"26263","last_name":"Silberhorn"}],"intvolume":"         4"},{"article_type":"original","author":[{"last_name":"Kirsch","id":"69553","first_name":"Michelle","full_name":"Kirsch, Michelle"},{"full_name":"Kießler, Christian","first_name":"Christian","id":"44252","last_name":"Kießler"},{"first_name":"Sebastian","full_name":"Lengeling, Sebastian","id":"44373","last_name":"Lengeling"},{"last_name":"Stefszky","id":"42777","full_name":"Stefszky, Michael","first_name":"Michael"},{"last_name":"Eigner","id":"13244","first_name":"Christof","full_name":"Eigner, Christof","orcid":"https://orcid.org/0000-0002-5693-3083"},{"full_name":"Herrmann, Harald","first_name":"Harald","id":"216","last_name":"Herrmann"},{"last_name":"Silberhorn","id":"26263","first_name":"Christine","full_name":"Silberhorn, Christine"}],"intvolume":"       193","citation":{"chicago":"Kirsch, Michelle, Christian Kießler, Sebastian Lengeling, Michael Stefszky, Christof Eigner, Harald Herrmann, and Christine Silberhorn. “Photorefraction and In-Situ Optical Cleaning in Various Types of LiNbO3 Waveguides.” <i>Optics &#38; Laser Technology</i> 193 (2025). <a href=\"https://doi.org/10.1016/j.optlastec.2025.114260\">https://doi.org/10.1016/j.optlastec.2025.114260</a>.","short":"M. Kirsch, C. Kießler, S. Lengeling, M. Stefszky, C. Eigner, H. Herrmann, C. Silberhorn, Optics &#38; Laser Technology 193 (2025).","ieee":"M. Kirsch <i>et al.</i>, “Photorefraction and in-situ optical cleaning in various types of LiNbO3 waveguides,” <i>Optics &#38; Laser Technology</i>, vol. 193, Art. no. 114260, 2025, doi: <a href=\"https://doi.org/10.1016/j.optlastec.2025.114260\">10.1016/j.optlastec.2025.114260</a>.","mla":"Kirsch, Michelle, et al. “Photorefraction and In-Situ Optical Cleaning in Various Types of LiNbO3 Waveguides.” <i>Optics &#38; Laser Technology</i>, vol. 193, 114260, Elsevier BV, 2025, doi:<a href=\"https://doi.org/10.1016/j.optlastec.2025.114260\">10.1016/j.optlastec.2025.114260</a>.","apa":"Kirsch, M., Kießler, C., Lengeling, S., Stefszky, M., Eigner, C., Herrmann, H., &#38; Silberhorn, C. (2025). Photorefraction and in-situ optical cleaning in various types of LiNbO3 waveguides. <i>Optics &#38; Laser Technology</i>, <i>193</i>, Article 114260. <a href=\"https://doi.org/10.1016/j.optlastec.2025.114260\">https://doi.org/10.1016/j.optlastec.2025.114260</a>","ama":"Kirsch M, Kießler C, Lengeling S, et al. Photorefraction and in-situ optical cleaning in various types of LiNbO3 waveguides. <i>Optics &#38; Laser Technology</i>. 2025;193. doi:<a href=\"https://doi.org/10.1016/j.optlastec.2025.114260\">10.1016/j.optlastec.2025.114260</a>","bibtex":"@article{Kirsch_Kießler_Lengeling_Stefszky_Eigner_Herrmann_Silberhorn_2025, title={Photorefraction and in-situ optical cleaning in various types of LiNbO3 waveguides}, volume={193}, DOI={<a href=\"https://doi.org/10.1016/j.optlastec.2025.114260\">10.1016/j.optlastec.2025.114260</a>}, number={114260}, journal={Optics &#38; Laser Technology}, publisher={Elsevier BV}, author={Kirsch, Michelle and Kießler, Christian and Lengeling, Sebastian and Stefszky, Michael and Eigner, Christof and Herrmann, Harald and Silberhorn, Christine}, year={2025} }"},"publication_status":"published","department":[{"_id":"288"},{"_id":"623"},{"_id":"15"}],"date_created":"2025-12-18T08:17:57Z","publisher":"Elsevier BV","year":"2025","publication_identifier":{"issn":["0030-3992"]},"language":[{"iso":"eng"}],"status":"public","_id":"63192","date_updated":"2025-12-18T08:27:13Z","title":"Photorefraction and in-situ optical cleaning in various types of LiNbO3 waveguides","abstract":[{"text":"Lithium niobate (LiNbO3) is a widely used material with several desirable physical properties, such as high second-order nonlinear optical and strong electro-optical effects. Thus LiNbO3 is used for various applications such as electro-optic modulation or nonlinear frequency conversion and mixing. But LiNbO3 also exhibits a strong photorefractive effect, which limits the intensity of the optical fields involved. Various approaches to reduce the photorefractive effect have been investigated, such as increasing the temperature, doping the crystal or using different waveguide designs in LiNbO3. Here, we present an analysis of the approach to increase the photorefractive damage threshold by using different waveguide designs. Contrary to previous claims and investigations, our SHG measurements revealed no significant difference in resistance to photorefractive damage when comparing conventional Ti-doped channel waveguides and Ti-doped diced ridge waveguides in LiNbO3. Furthermore, we have investigated the effect of photorefractive cleaning and curing using a light field at 532 nm. Here, we observe a reduction in the photorefractive effect at room temperature during and after SHG measurements, which is an easy alternative to conventional approaches.","lang":"eng"}],"doi":"10.1016/j.optlastec.2025.114260","user_id":"69553","oa":"1","main_file_link":[{"open_access":"1","url":"https://www.sciencedirect.com/science/article/pii/S0030399225018511?via%3Dihub"}],"publication":"Optics & Laser Technology","quality_controlled":"1","type":"journal_article","volume":193,"article_number":"114260"}]