A high-sensitive fiber curvature sensor using twin core fiber-based filter

作者：Yin G L; Lou S Q^*; Lu W L; Wang X

来源：Applied Physics B: Lasers and Optics , 2014, 115(1): 99-104.

DOI：10.1007/s00340-013-5578-z

A high-sensitive fiber curvature sensor is proposed and experimentally demonstrated in a large measurement range by using a twin core fiber (TCF)-based filter as sensor head. Applying the coupled-mode theory and equivalent refractive index model, we theoretically anticipate the "blue shift" of the transmission dips of the TCF-based filter when sensor head is bent. Experimentally, we fabricate an 86.9 mm TCF-based filter with a free spectral range of 49 nm and characterize its curvature performance by measuring the wavelength shift. A nonlinear "blue shift" of the wavelength is observed when we increase the curvature. The relationship between wavelength shift and curvature is a second-order polynomial function. In the range from 0 to 9.30 m(-1), the maximum sensitivity is up to -14.7 nm/m(-1). The measurement range can be further increased by selecting a shorter TCF.

• 出版日期2014-4
• 单位北京交通大学