Temperature sensing using an optical time domain reflectometer and mechanical long-period fiber gratings fabricated from a heat-shrinkable tube

Abstract

We develop a simple temperature sensing using an optical time domain reflectometer (OTDR) and a mechanical long-period fiber grating (LPFG) fabricated from a heat-shrinkable tube and a metric screw. The resonance loss of the fabricated LPFG is strongly dependent on temperature as temperature-dependent heat-shrinkage of the tube produces a change in the pressure applied to the fiber. In our proposed temperature sensor, the LPFG insertion loss due to a change in the pressure applied to the fiber is measured using an OTDR with a resonance wavelength. Both single-point and multi-point temperature sensing is successfully demonstrated experimentally.