title: Index profile determination of single-mode fiber by the phase contrast method: a proposed technique.
abstract: A nondestructive method is presented for determining index profiles of single-mode fibers. In this method, a plane wave is made to impinge laterally on the fiber, and the wave transmitted through the fiber is subjected to spatial filtering based on the phase contrast method which yields an image. From the intensity of the image, the phase shift of the transmitted wave and the index profile are determined. The conditions for obtaining a sufficient precision of measurement are surveyed, and the reconstruction of an index profile is carried out to verify the validity of the method.
authors.forename: K
authors.initials: K
authors.lastname: Tatekura