Wei Yong, Ren Puxi, Liu Chunlan, Tang Yixiong, Zhang Ziqiang, Liu Chunbiao, Shi Chen, Liu Zhihai
Opt Lett. 2023 Oct 1;48(19):5057-5060. doi: 10.1364/OL.500824.
At present, fiber strain sensors are mainly of the grating type and interference type, while there is relatively little research on fiber surface plasmon resonance (SPR) strain sensors. In this Letter, we propose a highly sensitive fiber SPR strain sensor based on an n-type structure. The strain changes the shape of the fiber n-type structure, causing the transmission mode of light in the fiber to change, thereby changing the SPR incidence angle and causing the SPR resonance valley wavelength to shift, achieving highly sensitive SPR strain sensing. The test results indicate that the strain sensing sensitivity of the proposed sensor reaches 21.33 pm/µε, and two n-type structures are connected in series to obtain a double n-type structure, further enhancing the strain sensing sensitivity to 33.44 pm/µε. This fiber strain sensor has advantages of high sensitivity, low temperature cross talk, strong structural stability, and low production cost, and is expected to become a new solution for wearable intelligent monitoring equipment and strain sensors in the aerospace field.
目前，光纤应变传感器主要为光栅型和干涉型，而对光纤表面等离子体共振（SPR）应变传感器的研究相对较少。在本信函中，我们提出了一种基于n型结构的高灵敏度光纤SPR应变传感器。应变改变了光纤n型结构的形状，导致光纤中光的传输模式发生变化，从而改变SPR入射角并使SPR共振谷波长发生偏移，实现高灵敏度的SPR应变传感。测试结果表明，所提出传感器的应变传感灵敏度达到21.33 pm/µε，将两个n型结构串联可得到双n型结构，进一步将应变传感灵敏度提高到33.44 pm/µε。这种光纤应变传感器具有灵敏度高、温度串扰低、结构稳定性强和生产成本低等优点，有望成为可穿戴智能监测设备及航空航天领域应变传感器的一种新解决方案。
