The invention describes an optical waveguide and a fiberoptic isolator
wherein the optical waveguide rotating the plane of polarization of
coupled light consists of a fiber core (11) exhibiting the Faraday effect,
a fiber cladding (3) and a coating (5) concentrically surrounding the
YIG-doped fiber core (11) and generating a permanent magnetic field. The
outer coating (5) is manufactured from a material that is magnetizable or
has magnetic properties, and the outer coating (5) is subdivided into two
half-shells whose magnetic orientations are mutually opposed.
