Simultaneous measurement of displacement and temperature using a PMF-based dual Mach-Zehnder interferometer.

Abstract

A dual Mach-Zehnder interferometer (MZI) based on polarization-maintaining fiber (PMF) is described for simultaneous measurement of displacement and temperature. Two orthogonal polarization components of a beam are simultaneously transmitted in the interferometer. The sensing configuration contains a short PMF section, a lens, and a mirror. The lens can transmit the slow polarization component and reflect the fast polarization component. Each polarization component exhibits a unique phase shift in response to changes in displacement and temperature, forming a dual MZI. Experimental results show that the resolutions of displacement and temperature are 60pm and 2×10-3°C, respectively, and measurement ranges of displacement and temperature can reach 20cm and 70°C. The experimental result demonstrates that there is no crosstalk between displacement and temperature, and high repeatability is demonstrated experimentally. This sensor allows multiparameter measurement, high resolution, wide measurement range, and good repeatability, conferring good application potential.