Experimental and theoretical analysis of curvature sensor based on cladding mode resonance with triple cladding quartz specialty fiber

A curvature sensor based on the triple cladding quartz specialty fiber (TCQSF) is proposed. The TCQSF is spliced between two single mode fibers. The curvature sensor is performed by cladding mode resonance. The TCQSF with the length of 10 mm, 35 mm, and 50 mm is prepared and applied to the curvature measurement experiment. The bending model is created and analyzed by the finite element method theoretically. The experiment results show that the curvature sensitivity of sensor with different length are −1.83001 nm/m−1, −1.56231 nm/m−1 and −1.0114 nm/m−1 in the curvature range of 0∼0.94m−1.