Ultrasensitive temperature sensor with Vernier-effect improved fiber Michelson interferometer

A novel fiber Michelson interferometer (FMI) based on parallel dual polarization maintaining fiber Sagnac interferometers (PMF-SIs) is proposed and experimentally demonstrated for temperature sensing. The free spectral range (FSR) difference of dual PMF-SIs determines the FSR of envelope and sensitivity of the sensor. The temperature sensitivity of parallel dual PMF-SIs is greatly enhanced by the Vernier effect. Experimental results show that the temperature sensitivity of the proposed sensor is improved from -1.646 nm/degrees C (single PMF-SI) to 78.984 nm/degrees C (parallel dual PMF-SIs), with a magnification factor of 47.99, and the temperature resolution is improved from +/- 0.03037 degrees C to +/- 0.00063 degrees C by optimizing the FSR difference between the two PMF-SIs. Our proposed ultrasensitive temperature sensor is with easy fabrication, low cost and simple configuration which can be implemented for various real applications that need high precision temperature measurement. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

A novel fiber Michelson interferometer for temperature sensing based on parallel dual polarization maintaining fiber Sagnac interferometers is proposed and experimentally demonstrated. The temperature sensitivity and resolution are greatly enhanced using the Vernier effect, showing significant improvement compared to single polarization maintaining fiber Sagnac interferometers.