Open AccessAll-sapphire-based fiber-optic pressure sensor for high-temperature applications based on wet etching
Author(s) -
Zhiqiang Shao,
Yiping Wu,
Shuang Wang,
Chaozhu Zhang,
Zhiqiang Sun,
Mengyao Yan,
Yingqi Shang,
Erdong Song,
Zhiyuan Liu
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.417246
Subject(s) - materials science , sapphire , optics , etching (microfabrication) , pressure sensor , surface roughness , interferometry , surface finish , optoelectronics , surface pressure , laser , composite material , layer (electronics) , physics , mechanics , thermodynamics
In this paper, we proposed an all-sapphire-based extrinsic Fabry-Perot interferometer (EFPI) pressure sensor based on an optimized wet etching process, aiming to improve the quality of the interference signal. The sapphire pressure sensitive diaphragm (SPSD) was fabricated by wet etching solutions with different mixture ratios of H 3 PO 4 and H 2 SO 4 at 280°C. The differences of mixture ratios affect the surface roughness of SPSD. SPSDs with surface roughness of 3.91nm and 0.39nm are obtained when the mixture ratios of H 3 PO 4 and H 2 SO 4 is 1:1 and 1:3, respectively. We constructed pressure sensing test system adopting these two kinds of SPSD and performed comparative test. The experiment results show that the demodulation jump can be solved and cavity length fluctuation is decreased to ±5nm when the surface roughness of SPSD is 0.39nm.