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Updated: Jul 7, 2026
A Random-displacement Measurement by Combining a Magnetic Scale and Two Fiber Bragg Gratings
Published on: September 30, 2019
Intensity-modulated fiber Bragg grating sensor system based on radio-frequency signal measurement
Xinyong Dong1, Li-Yang Shao, H Y Fu
1Photonics Research Centre, Department of Electrical Engineering, The Hong Kong Polytechnic University, Hong Kong. eexydong@polyu.edu.hk
Abstract:
An intensity-modulated, fiber Bragg grating (FBG) sensor system based on radio-frequency (RF) signal measurement is presented. The RF signal is generated at a photodetector by two modulated optical signals reflected from the sensing FBG and a reference FBG. Wavelength shift of the sensing FBG changes intensity of the RF signal through changing the delay between the two optical signals, with temperature effect being compensated automatically by the reference FBG. It also exhibits important features including potentially high-speed measurement, low cost, and adjustable sensitivity. In the experiment, strain measurement with a maximum sensitivity of -0.34 microV/micro epsilon has been achieved.
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