Pressure and temperature sensors based on an over-discharged spliced polarization-maintaining photonic crystal fiber

Abstract

A polarization maintaining-photonic crystal fiber (PM-PCF) sensor for air pressure and temperature measurement is proposed by over-discharge splicing a section of PM-PCF to a single-mode fiber. This simple splicing procedure generates an air bubble in the PM-PCF at the splicing spot. The bubble and the PM-PCF cavities cascading sensor operates on three beams interference and demonstrates an envelope in the reflection spectrum. The pressure measurement results show that the resonance wavelength is linearly red shift with the gas pressure increasing, and the pressure sensitivity is nonlinearly increasing as the bubble length increases. A maximum sensitivity of the resonance wavelength shift is 4.05 nm/MPa in the range of 0.1 ∼ 0.9 MPa obtained with a sensor sample with 65µm bubble length. This sensor also shows 25.3 times more sensitivity amplification than the non-bubble PM-PCF sensor. Besides, the sensor also shows response to temperature, in the temperature range of 25 ∼ 500°C, the maximum sensitivity with 10pm/°C is obtained. Additionally, the proposed sensor also shows good repeatability and stability. In conclusion, the simple PM-PCF sensor can be applied in high-pressure and high-temperature monitoring in harsh environments.