High-Sensitivity Gas Pressure Sensor with Low Temperature Cross-Crosstalk Based on Vernier Effect of Cascaded Fabry-Perot Interferometers

Abstract

A gas pressure sensor composed of cascaded Fabry-Perot interferometers (FPIs) based on Vernier effect was demonstrated. Two hollow silica tubes (HSTs) with different inner diameters were used to construct the FP cavities, and spliced with single-mode fiber (SMF) to make a gas pressure sensor with a closed cavity FPI and an open cavity FPI in series. The experimental results show that the proposed sensor achieves a high gas pressure sensitivity of -44.31 nm/MPa in the range of 0-2.2 MPa due to the Vernier amplification effect and a very low temperature cross-sensitivity of -0.6 KPa/℃. This sensor has high sensitivity, wide measurement range, small temperature crosstalk, good robustness and low production cost in gas pressure measurement.

Keywords: fiber sensor, gas pressure sensor, Fabry-Perot interferometer, Vernier effect