Chalcogenide fiber-based distributed temperature sensor with sub-centimeter spatial resolution and enhanced accuracy

Abstract

We demonstrate a sub-centimeter spatial resolution fiber-based distributed temperature sensor with enhanced measurement accuracy and reduced acquisition time. Our approach employs time domain analysis of backscattered Stokes and anti-Stokes photons generated via spontaneous Raman scattering in a chalcogenide (ChG) As2S3 fiber for temperature monitoring. The sensor performance is significantly improved by exploiting the high Raman coefficient and increased refractive index of the ChG fiber. We achieve a temperature uncertainty of ± 0.65 °C for a short measurement time of only 5 seconds; whilst the detection uncertainty is less than ± 0.2 °C for a longer integration time of 2 minutes. We also investigate the optimum Stokes and anti-Stokes bands for optimal sensing performance. Our theoretical analysis shows that a small detuning frequency regime from a pump is more suitable for rapid measurements while a large detuning regime provides higher temperature resolution.