High-sensitivity gas pressure sensor with low temperature cross-talk based on Vernier effect of cascaded Fabry-Perot interferometers

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/celcius. This sensor has high sensitivity, wide measurement range, small temperature crosstalk, good robustness and low production cost in gas pressure measurement.