A new cascaded structure based on two long-period fiber gratings (LPFGs) for simultaneous measurement of strain and temperature is proposed and studied. The proposed structure is cascaded by a LPFG and a S-type long-period fiber grating (S-LPFG). The LPFG is fabricated using the CO₂ laser by etched method. The S-LPFG is fabricated using the CO₂ laser by polished method. The grooves of the S-LPFG are staggered in opposite directions, and this special geometry results in high strain sensitivity. The experimental results show that the strain sensitivities of the two resonant dips of the cascaded structure are 16.31 pm/ $\mu \varepsilon $ and −2.42 pm/ $\mu \varepsilon $ with the range of 0- $500~\mu \varepsilon $ , respectively. Strain sensitivity varies greatly between two dips and the resonant wavelength shifts in the opposite direction. The temperature sensitivities of the two resonant dips of the cascaded structure are 59.73 pm/°C and 60.38 pm/°C, respectively. Since the difference between temperature and strain sensitivity, matrix method can be used for simultaneous measurement of two parameters. The feasibility of the cascaded structure has been experimentally demonstrated for the simultaneous measurement. Therefore, the cascaded structure has the potential to measure strain and temperature simultaneously.

中文翻译：

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一种用于同时测量应变和温度的新型传感器

提出并研究了一种基于两个长周期光纤光栅 (LPFG) 的新级联结构，用于同时测量应变和温度。所提出的结构由 LPFG 和 S 型长周期光纤光栅 (S-LPFG) 级联而成。LPFG 是使用 CO ₂激光器通过蚀刻方法制造的。S-LPFG 是使用 CO ₂激光器通过抛光方法制造的。S-LPFG 的凹槽在相反方向上交错排列，这种特殊的几何形状导致了高应变敏感性。实验结果表明，级联结构的两个共振倾角的应变灵敏度为16.31 pm/ $\mu \varepsilon $ 和-2.42 pm/ $\mu \varepsilon $ 范围为 0- $500~\mu \varepsilon $ ， 分别。应变灵敏度在两个倾角之间变化很大，并且谐振波长在相反方向上偏移。级联结构的两个谐振倾角的温度灵敏度分别为 59.73 pm/°C 和 60.38 pm/°C。由于温度和应变灵敏度的差异，矩阵法可用于同时测量两个参数。级联结构的可行性已被实验证明用于同时测量。因此，级联结构具有同时测量应变和温度的潜力。