Sumitomo Electric Research Triangle, Inc.

Sumitomo Electric Fiber Optics Corporation

Masayuki Nishimura

Eric L Buckland

William H Hatton

A simultaneous bi-directional OTDR optical fiber measurement method wherein a test fiber is spliced between a launch fiber and a termination fiber which is provided with a reflective coating at its terminal end. A laser light pulse is introduced into the launch fiber and the forward trace signal and reverse trace signal from the light pulse are detected. A correction is applied to the reverse trace signal to account for reflectivity originating at the fiber input end so that an accurate measurement can be made of certain fiber characteristics of a single-mode optical fiber.

Simultaneous bi-directional optical time domain reflectometry method

A method is disclosed for determining the refractive index profile of an optical fiber wherein light from an intense optical source is focused at the bare fiber end portion of the test fiber. A small amount of light will be coupled into the optical fiber where for the short length of uncoated fiber only cladding modes are excited. The index of refraction is determined directly by analyzing the intensity distribution emitted from the optical fiber with a lens system having a limited numerical aperture.

Method of measuring the refractive index profile of optical fibers

A method for measuring certain geometrical properties of an optical fiber wherein the coating is removed from adjacent one end of the fiber, a high intensity light source is focused at the bare fiber and coating interface in order to couple scattered light into the optical fiber cladding and the intensity distribution of the transmitted light at the end face of optical fiber is analyzed. In this fashion nonuniformities on the end face of the optical fiber will not substantially affect the accuracy of measurements of geometrical properties of the cladding region of the optical fiber.

Growing community of inventors

Durham, NC, United States of America

Masayuki Nishimura