@article{20189,
  abstract     = {{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.}},
  author       = {{Hammer, Manfred and Ebers, Lena and Förstner, Jens}},
  issn         = {{0306-8919}},
  journal      = {{Optical and Quantum Electronics}},
  keywords     = {{tet_topic_waveguides}},
  title        = {{{Hybrid coupled mode modelling of the evanescent excitation of a dielectric tube by semi-guided waves at oblique angles}}},
  doi          = {{10.1007/s11082-020-02595-z}},
  volume       = {{52}},
  year         = {{2020}},
}