提出一种新型取样布拉格光纤光栅传感器, 用于温度和轴向应变的传感。为了制作该传感器, 利用特种光纤熔接机在单模光纤上制造出单螺旋扭转结构, 然后在单螺旋结构上利用紫外激光侧写和相位掩模板技术刻写布拉格光纤光栅。该取样光栅反射谱具有等间距、窄带宽的特点, 并且可通过调整单螺旋扭转率来自由改变取样周期。通过实验研究了传感器对温度和光纤轴向应变的响应, 结果表明：当单螺旋扭转周期P=504.0 μm(扭转率α=12.47 rad/mm), 布拉格光栅周期Λ=544.6 nm, 器件长度L=5.0 mm时, 温度和轴向应变灵敏度分别为10.12 pm/℃和1.12 pm/με。较同类型取样光栅传感器, 该传感器具有制作简单、灵活性高、稳定性高和成本低的优点, 且在多波长光纤激光器和多通道光谱滤波器等领域展现出应用潜力。

A kind of novel sampled fiber Bragg grating (SFBG) sensor for temperature and axial strain sensing is proposed and demonstrated. In order to fabricate the SFBG, we make a single helical twist structure on a standard single-mode fiber by a special fiber fusion splicer, and then inscribe a fiber Bragg grating on the twist structure based on the UV-side illumination and the phase mask technique. The reflective spectrum of the SFBG has the characteristics of equal spacing and narrow bandwidth, and can be freely modified by adjustment of the twist rate of the fiber. We experimentally investigate the temperature and axial strain responses of the SFBG, and the results show that when helical twist period is P=504.0 μm (torsional rate is α=12.47 rad/mm), the period of FBG is Λ=544.6 nm, and the device length is L=5.0 mm, the measured sensitivities for temperature and axial strain are 10.12 pm/℃ and 1.12 pm/με, respectively. Compared with the counterparts, the SFBG has the advantages of simple fabrication, high flexibility, high stability and low cost. It has potential applications in multi wavelength fiber lasers and multi-channel spectral filters.