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oai:docta.ucm.es:20.500.14352/649422025-07-16T17:53:19Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Fernández Álvarez-Estrada, Ramón author Calvo Padilla, María Luisa author 1983 We study anisotropic cylindrical dielectric waveguides under the following conditions: (1) their cross section Ω has arbitrary shape; (2) the dielectric permittivity tensor ε has discontinuities at the boundaries, as well as a graded spatial variation; (3) Ω is small, and ε minus the unit 3 × 3 matrix (I) is small and smooth, so that only one pair of propagation modes is allowed. A general and exact dispersion relation for the propagation modes is derived, using integral equation techniques and the long wavelength singularity of the free-space Green's function in two dimensions. We present approximate explicit solutions of the dispersion relation to first order in (ε− I), which exhibit a logarithmic dependence and birefringence, in general. Some numerical estimates are also given. Approximate dispersion relations up to and including second order in (ε − I) are also discussed. The scattering problem is treated briefly. 0030-3909 10.1080/713821213 https://hdl.handle.net/20.500.14352/64942 http://dx.doi.org/10.1080/713821213 http://www.tandfonline.com Single-mode Anisotropic Cylindrical Dielectric Waveguides