Improved-bonding linearly chirped fiber grating for a high-sensitivity surface-mounted strain sensor.
For a competitive sensor, both the sensitivity enhancement and calibration convenience are important. However, for surface-mounted fiber grating strain sensors, researchers in previous studies have seldom addressed these two capabilities simultaneously. Using the coupled-mode theory, we calculated the voltage signals from the filtered spectral-power interrogation system for a fiber Bragg grating with a glued grating or with a glue-free grating subject to different strain fields. Under a grating zone (the targeted surface), a one-dimensional linearly varied strain field, described by both the parameters of the average strain and the strain gradient, was considered. Finally, a simple and easy formula is provided (the improved-bonding linearly chirped fiber grating) to achieve both the sensitivity enhancement and calibration convenience at the same time for the strain sensor.
Department of Mechanical Engineering, National Taiwan University, Section 4, Number 1, Roosevelt Road, Taipei 106, Taiwan.
Gwo-Shyang
GS
Hwang
Ding-Wei
DW
Huang
Chien-Ching
CC
Ma