Multiparameter Sensor Based on Cascaded Micro-Tapered Long-Period Fiber Gratings
Chenghui Yang, Yan Kuai, Zhigang Cao, Feng Xu, Yu Liu, Kang Xie, Siqi Li, Benli Yu, Zhijia Hu
Abstract
To realize multiparameter simultaneous sensing measurement and eliminate cross-sensitivity, we cascade three micro-tapered long-period fiber grating (TLPG) sensors and analyze the transmission characteristics and sensing capabilities of cascaded micro-TLPGs (CTLPGs) in detail. Based on the modulation of the resonant wavelength of the sensor by the change of the surrounding environment, the synchronous real-time detection of refractive index (RI), temperature, and liquid level is realized. The CTLPG sensor not only inherits the advantages of TLPG sensors and reduces the influence of cross-sensitivity when measuring multiparameters but also improves the sensitivity and accuracy of the sensor. The experimental results show that the maximum RI sensitivity is 693 nm/RIU, the maximum temperature sensitivity is −93 pm/°C, and the maximum liquid-level sensitivity is 12 nm/mm. The sensor has a simple structure, low manufacturing cost, high sensitivity, and potential applications in monitoring ocean temperature, salinity, and depth.