A method of inducing birefringence in an optical waveguide is disclosed
wherein the waveguide cladding is irradiated with energy of a sufficient
intensity so as to induce a stress in the optical waveguide so as to
cause a multitude of spaced stress induced regions within the cladding of
the optical waveguide such that there are 10 to 5000 spaced regions per
mm and wherein the stress induced regions are proximate the core greater
than 2 microns distance from the core-cladding interface. This waveguide
has numerous uses, for example a fiber sensor.