【摘要】 报道了一种用高频CO2 激光脉冲写入的新型长周期光纤光栅 (LPFG) .发现该LPFG具有独特的应变、温度、弯曲、扭曲和横向负载特性 .分析表明这些特性与单侧CO2 激光加热导致光栅横截面折射率分布不均匀有关 .基于这些独特的特性提出了几种新型的LPFG传感器 :1)能彻底解决弯曲与其他参量之间交叉敏感问题的弯曲不敏感的传感器 ;2 )不仅能绝对测量扭曲率而且能判断扭曲方向的扭曲传感器 ;3 )单个LPFG实现温度和横向负载同时测量的传感器 .这些新型的传感器具有方法简单易行、体积小、能埋入智能材料的优点 ,可实现对工程结构的实时监测 ,具有广泛的应用前景更多还原

【Abstract】 In this paper, we report novel long-period fibre gratings (LPFGs) written by focused high-frequency CO 2 laser pulses. A number of unique characteristics of such a LPFG, such as stroin, temperature, bend, torsion and transverse-load, etc., are observed by experiment, for the first time to our knowledge. These unique features are mainly due to the asymmetrical distribution of the refractive index on the cross section of the LPFG induced by high-frequency CO 2 laser pulses. Based on these unique characteristics, we have proposed a novel bend-insensitive LPFG sensor that could solve the problem of cross-sensitivity between bend and other measurements, a novel torsion sensor that can realize absolute measurement of twist rate and a load sensor that can achieve simultaneous measurement of transverse load and temperature using a single LPFG element.更多还原