This paper proposes a long period fiber grating (LPFG) pressure sensor based on mode transition, consists of LPFG and two polymer films. The inner layer of polyvinyl alcohol (polyvinyl alcohol, PVA) with high refractive index properties can be tuned to operate within the LPFG’s mode transition region. The outer layer of porous polydimethylsiloxane (PDMS) can be used as a pressure-sensitive material for the sensor. Experimental results show that the sensor achieves a sensitivity of 612 pm/kPa when the PVA thickness is 244 nm, which is approximately 50 times higher than that of a conventional LPFG sensor without excitation mode transition. To address temperature sensitivity inherent in both the PVA and PDMS, a fiber Bragg grating (FBG) is connected in series for temperature compensation. The proposed LPFG pressure sensor based on mode transition exhibits high sensitivity and a simple fabrication process, making it a promising candidate for applications in high-precision pressure sensing.
WANG Chaoyuan
,
WU Huayan
,
ZHOU Yi
,
HUANG Heyu
,
ZHOU Ai
. Research on Performance of LPFG Gas Pressure Sensor Based on Mode Transition[J]. Journal of Applied Sciences, 2025
, 43(5)
: 721
-729
.
DOI: 10.3969/j.issn.0255-8297.2025.05.001
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