摘要： Nonreciprocal propagation in optical fibers presents practical interest. The present work treats the problem of nonreciprocal propagation in nonabsorbing cylindrically layered structures at axial magnetization characterized by magnetooptic electrical permittivity, ?ε, and magnetic permeability, ?μ, tensors, using transverse circularly polarized representation. The solutions to the vector Helmholtz equation are expressed analytically as functions of circular cylindrical coordinates (cid:37), ?, and z. The results are applied to a magnetooptic circular cylindrical waveguide and illustrated on fiber waveguides with an yttrium iron garnet (YIG) core and a cladding formed by gallium substituted yttrium iron garnet (GaYIG) at the optical communication wavelength of 1.55 μm. The propagation distance in the waveguide for a π/4 azimuth rotation of a transverse linearly polarized incident wave on the waveguide axis required in isolators is about 100 μm.