Related Experiment Video
Updated: Jun 18, 2026

A Random-displacement Measurement by Combining a Magnetic Scale and Two Fiber Bragg Gratings
Published on: September 30, 2019
Single fiber Bragg grating sensor with two sections of different diameters for longitudinal strain and temperature
Samir K Mondal1, Umesh Tiwari, Gopal C Poddar
1Central Scientific Instruments Organisations, Sec.-30C, Chandigarh, India.
Abstract:
A single fiber Bragg grating (FBG) sensor with two sections of different diameters is proposed and experimentally demonstrated for discrimination and measurement of strain and temperature. A section of single FBG is etched in hydrofluoric acid solution to reduce diameter of the fiber by factor of <1/2 to increase its strain sensitivity. Different shifts of the Bragg wavelengths of chemically etched and nonetched gratings caused by different strain sensitivities are used to discriminate and measure strain and temperature. Maximum errors of +/-13 microepsilon (microstrain) and +/-1 degrees C are reported over 1700 microepsilon and 60 degrees C measurement ranges, respectively. Depending upon the diameter of the etched fiber grating, the design can also discriminate nanostrain from temperature.
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