Estimation of losses caused by sidewall roughness in thin-film lithium niobate rib and strip waveguides Hammer, Manfred Babel, Silia Farheen, Henna Padberg, Laura Scheytt, J. Christoph Silberhorn, Christine Förstner, Jens tet_topic_waveguide ddc:530 Samples of dielectric optical waveguides of rib or strip type in thin-film lithium niobate (TFLN) technology are characterized with respect to their optical loss using the Fabry-Pérot method. Attributing the losses mainly to sidewall roughness, we employ a simple perturbational procedure, based on rigorously computed mode profiles of idealized channels, to estimate the attenuation for waveguides with different cross sections. A single fit parameter suffices for an adequate modelling of the effect of the waveguide geometry on the loss levels. Optica Publishing Group 2024 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/54668 https://ris.uni-paderborn.de/download/54668/54669 Hammer M, Babel S, Farheen H, et al. Estimation of losses caused by sidewall roughness in thin-film lithium niobate rib and strip waveguides. <i>Optics Express</i>. 2024;32(13):22878. doi:<a href="https://doi.org/10.1364/oe.521766">10.1364/oe.521766</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1364/oe.521766 info:eu-repo/semantics/altIdentifier/issn/1094-4087 info:eu-repo/grantAgreement/EC/231447078 info:eu-repo/grantAgreement/EC/231447078 info:eu-repo/grantAgreement/EC/231447078 info:eu-repo/grantAgreement/EC/PROFILNRW-2020-067 info:eu-repo/semantics/openAccess