Guzman-Sepulveda J R, May-Arrioja D A
Fiber and Integrated Optics Laboratory, UAM Reynosa-Rodhe, Universidad Autónoma de Tamaulipas, Carr Reynosa-San Fernando S/N, Reynosa, Tamaulipas 88779, México.
Opt Express. 2013 May 20;21(10):11853-61. doi: 10.1364/OE.21.011853.
A curvature fiber optic sensor using a two-core fiber (TCF) is proposed and demonstrated. The TCF is designed to operate as a directional coupler with one core located exactly at the center of the fiber and the other off-axis, but close to the center of the fiber. This design allows straightforward splicing of the TCF to single mode fibers (SMF), and alignment of the off-axis core is not strictly required for optimum operation. The sensor is fabricated by simply splicing a 5 cm long section of TCF between two SMF sections, which provides a sinusoidal spectral response. When the fiber is bent, the coupling parameters are modified due to stress-optic and effective length effects, effectively blue-shifting the sinusoidal spectral response of the sensor and allowing for the measurement of curvature. The sensor exhibits linear response and a sensitivity of -137.87 nm/m(-1) for curvature ranging from 0 to 0.27 m(-1), making it suitable to measure small curvatures with high sensitivity.
提出并演示了一种使用双芯光纤（TCF）的曲率光纤传感器。该双芯光纤被设计成作为一个定向耦合器工作，其中一个芯恰好位于光纤中心，另一个芯偏离轴线，但靠近光纤中心。这种设计使得双芯光纤能够直接与单模光纤（SMF）拼接，并且对于最佳操作而言，并不严格要求偏离轴线的芯进行对准。该传感器通过简单地在两段单模光纤之间拼接一段5厘米长的双芯光纤来制造，这提供了正弦光谱响应。当光纤弯曲时，由于应力 - 光学和有效长度效应，耦合参数会发生改变，从而有效地使传感器的正弦光谱响应发生蓝移，并能够测量曲率。该传感器呈现线性响应，对于0至0.27米⁻¹范围内的曲率，灵敏度为 -137.87纳米/米⁻¹，使其适合以高灵敏度测量小曲率。
