Hybrid coupled mode modelling of the evanescent excitation of a dielectric tube by semi-guided waves at oblique angles Hammer, Manfred Ebers, Lena Förstner, Jens tet_topic_waveguides ddc:530 A dielectric step-index optical fiber with tube-like profile is considered, being positioned with a small gap on top of a dielectric slab waveguide. We propose a 2.5-D hybrid analytical/numerical coupled mode model for the evanescent excitation of the tube through semi-guided waves propagating in the slab at oblique angles. The model combines the directional polarized modes supported by the slab with analytic solutions for the TE-, TM-, and orbital-angular-momentum (OAM) modes of the tube-shaped fiber. Implementational details of the scheme are discussed, complemented by finite-element simulations for verification purposes. Our results include configurations with resonant in-fiber excitation of OAM modes with large orbital angular momentum and strong field enhancement. 2020 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/20189 Hammer M, Ebers L, Förstner J. Hybrid coupled mode modelling of the evanescent excitation of a dielectric tube by semi-guided waves at oblique angles. <i>Optical and Quantum Electronics</i>. 2020;52. doi:<a href="https://doi.org/10.1007/s11082-020-02595-z">10.1007/s11082-020-02595-z</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1007/s11082-020-02595-z info:eu-repo/semantics/altIdentifier/issn/0306-8919 info:eu-repo/semantics/altIdentifier/issn/1572-817X info:eu-repo/semantics/closedAccess