Asymptotic Analysis of Weakly Guiding Anisotropic Optical Fibers

摘要

The asymptotic power series method is applied to wave propagation in a transversely anisotropic optical fiber. The dielectric waveguide structure may be arbitrarily inhomogeneous and anisotropic in the transverse plane. The dielectric tensor of the guide is assumed to be only slightly different from that of the surrounding material. It is shown that the asymptotic modes are solutions to a vector differential equation of Schrodinger type. The isotropic fiber has degenerate solutions and is more complicated to solve. The different asymptotic dependence of the birefringence in isotropic and anisotropic fibers is demonstrated. Isotropic and anisotropic fibers are studied by variational techniques, emphasizing anisotropic fibers whose solutions can be obtained from that of an isotropic fiber through parameter transformation.