3M Innovative Properties Company

Minnesota Mining and Manufacturing Company

University System of Maryland

Harmeet Singh

Paul Eric Sanders

Gary A Ball

James S Sirkis

Bryon J Cronk

James Craig Novack

Wayne Francis Varner

Charles W Haggans

Bruce A Rabine

The present invention is a process for manufacturing an optical fiber Bragg grating, which in a preferred embodiment includes the steps of: (a) removing at least a portion of a removable coating on an optical fiber element in at least one predetermined section to sufficiently expose the optical fiber in the section for a subsequent treatment by a source of optical radiation; (b) fixing the at least one section with respect to the source of optical radiation; (c) directing optical radiation from the source into the optical fiber to produce at least one Bragg grating in the at least one section; and (d) covering the at least one section. The present invention also extends to an apparatus for carrying out the process steps described above, which includes means for coating removal, means for fiber immobilization, means for writing a Bragg grating, and means for packaging.

Incremental method of producing multiple UV-induced gratings on a single optical fiber

A tape to be mounted on a workpiece includes an elongated support ribbon and an optical fiber attached to the support ribbon.

Sensing tapes for strain and/or temperature sensing

Cascaded waveguide sensors with different sensitivities to temperature and strain produce independent temperature and strain measurements. In one embodiment a first sensor is formed of a first optical material having a corresponding first sensible thermomechanical response and a second sensor is formed of a second optical material having a corresponding second sensible thermomechanical response. The first and second thermomechanical responses are sufficiently different so as to produce independent temperature and strain measurements. Particular embodiments employ intrinsic or extrinsic Fabry-Perot interferometers (IFP, EFP),sensors, in-line fiber etalon (ILFE) sensor and a fiber-optic Bragg grating.

Simultaneous measurement of temperature and strain using optical sensors

An optical fiber filter including a length of single mode fiber having an operating wavelength .lambda..sub.0. Fiber designs may include a depressed inner clad fiber, a photosensitive matched inner clad fiber or a photosensitive depressed inner clad fiber. The length of fiber includes a core, an inner cladding, an outer cladding and an azimuthally asymmetric grating. The core allows the existence of a LP.sub.01 core mode having an effective index of n.sub.eff,01 and the cladding allows the existence of a LP.sub.1m cladding mode, m.gtoreq.1. The core has an index of refraction n.sub.co and a radius A. The inner cladding has an index of refraction n.sub.ic, an inner radius A, an outer radius AB, a thickness W, where W=AB-A, and a refraction difference .DELTA.n-, where .DELTA.n- is the difference between n.sub.ic and n.sub.oc and n.sub.co &gt;n.sub.oc &gt;n.sub.ic. The inner cladding may be photosensitive to a radius R.sub.grat and have a fractional photosensitivity .gamma.. The outer cladding generally laterally surrounds the inner cladding and has an inner radius AB, an outer radius B, and an index of refraction n.sub.oc, where .DELTA.n.sub.+ is the difference between n.sub.co and n.sub.oc. The grating has an effective tilt angle .theta. and a period (.LAMBDA.), where .LAMBDA..ltoreq.(.lambda..sub.0 cos .theta.)/(2n.sub.eff,01), the maximum relative coupling coefficient for the cladding mode max(RCC.sub.1m) being greater or equal to 0.2 and the ratio of peak reflectivities for the cladding mode and the core mode RR being greater or equal to 1.

Waveguide narrowband rejection filter

Growing community of inventors

Simsbury, CT, United States of America

Harmeet Singh