LOW SCATTERING LOSS HIGH TEMPERATURE STABLE FIBER BRAGG GRATING SENSOR BASED ON MICROPORE FORMATION AND METHOD FOR PRODUCING SAME

• Main Authors: HNATOVSKY, Cyril, ABDUKERIM, Nurmemet, LU, Ping, DING, Huimin, COULAS, David, MIHAILOV, Stephen, DE SILVA, Kasthuri, WALKER, Robert, GROBNIC, Dan
• Format: Patent
• Language: English
• Published: 11.01.2024
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; MATERIALS THEREFOR; MEASURING; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; TARIFF METERING APPARATUS; TESTING

A method and apparatus for inscribing a high-temperature stable Bragg grating in an optical waveguide, comprising the steps of: providing the optical waveguide; providing electromagnetic radiation from an ultrashort pulse duration laser, wherein the wavelength of the electromagnetic radiation has a characteristic wavelength in the wavelength range from 150 nanometers (nm) to 2.0 micrometers (μm); providing cylindrical focusing optics; providing a diffractive optical element that when exposed to the focused ultrashort laser pulse, creates an interference pattern on the optical waveguide, wherein the irradiation step comprises irradiating a surface of the diffractive optical element with the focused electromagnetic radiation, the electromagnetic radiation incident on the optical waveguide, from the diffractive optical element, being sufficiently intensive to cause permanent (Type II) change in the index of refraction within multiple Bragg grating planes in the core of the optical waveguide resulting from at least one micropore.