Multiparameter measurement sensor based on no-core fiber.

This paper proposes a no-core-single-mode-no-core Mach-Zehnder fiber sensor. In this sensor, two no-core fibers serve as input and output couplers, and the middle single-mode fiber serves as a sensing arm. Using finite element simulation and theoretical analysis, the optimal length of the couplers and the sensing arm are determined. High-order modes excited by no-core optical fiber propagate through the cladding of the single-mode fiber, which is affected by the ambient temperature and applied force. The trough of different interference orders of the transmission spectrum is selected as a research object to realize the measurement of curvature and temperature, strain and temperature with the sensing matrix.