High-sensitivity fiber-optic Fabry-Perot transverse load sensor based on bubble microcavity

A miniature fiber optic transverse load sensor based on bubble microcavity is fabricated and demonstrated for transverse load sensing. The bubble is fabricated by using of the arc discharge to fuse a section of hollow capillary, which is spliced to a single mode fiber (SMF) end. In the entire fabrication process, only a fusion splicer is needed. When the transverse load is applied to the microcavity, the cavity length of the sensor is changed, then the load can be detected by investigating the cavity length. The white light interference (WLI) demodulation method based on digital cross-correlation technology is used to demodulate the cavity length, and the transverse load sensitivity and temperature sensitivity of the sensor are tested. For the 145 mu m-long bubble microcavity, the sensor has a good linear response in the load range of 0 N to 0.88 N. A high cavity length-transverse load sensitivity of 311.3 nm/N and a high resolution of 0.19 mN are obtained. Moreover, the temperature sensitivity of the sensor is very low, and it does not need temperature compensation in practical use. Due to the miniature size, low cost, easy fabrication, high sensitivity, and low temperature sensitivity, the sensor has a high potential for transverse load sensing.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This article presents a miniature fiber optic transverse load sensor based on a bubble microcavity. It features small size, low cost, easy fabrication, high sensitivity, and low temperature sensitivity, making it highly promising for transverse load sensing.