Highly sensitive curvature sensor based on singlemode-multimode-singlemode fiber structures

摘要

A kind of highly sensitive curvature sensor based on singlemode-multimode-singlemode (SMS) fiber structure is demonstrated. The wavelength or intensity of the interference valley may vary with the curvature remarkably, which can be utilized for curvature sensing. The wavelength shift of the SMS structure with 26 mm-long multimode fiber (MMF) is very sensitive to the curvature. The measurement sensitivity of -13.17 nm/m(-1) is obtained in the curvature range of 0.60-1.55 m(-1). While for the SMS structure with 48 mm-long MMF, the intensity rather than the wavelength shift of the interference valley is very sensitive to the curvature. The measurement sensitivity of 24.64 dB/m(-1) in the curvature range of 0.22-0.89 m(-1) is achieved.