Spatially Modulated Fiber Speckle for High-Sensitivity Refractive Index Sensing
Penglai Guo,
Huanhuan Liu,
Zhitai Zhou,
Jie Hu,
Yuntian Wang,
Xiaoling Peng,
Xun Yuan,
Yiqing Shu,
Yingfang Zhang,
Hong Dang,
Guizhen Xu,
Aoyan Zhang,
Chenlong Xue,
Jiaqi Hu,
Liyang Shao,
Jinna Chen,
Jianqing Li,
Perry Ping Shum
Affiliations
Penglai Guo
School of Computer Science and Engineering, Faculty of Innovation Engineering, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau 999078, China
Huanhuan Liu
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Zhitai Zhou
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Jie Hu
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Yuntian Wang
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Xiaoling Peng
School of Computer Science and Engineering, Faculty of Innovation Engineering, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau 999078, China
Xun Yuan
School of Computer Science and Engineering, Faculty of Innovation Engineering, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau 999078, China
Yiqing Shu
Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, Foshan University, 18 Jiang-Wan-Yi-Lu, Foshan 528000, China
Yingfang Zhang
School of Computer Science and Engineering, Faculty of Innovation Engineering, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau 999078, China
Hong Dang
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Guizhen Xu
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Aoyan Zhang
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Chenlong Xue
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Jiaqi Hu
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Liyang Shao
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Jinna Chen
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
Jianqing Li
School of Computer Science and Engineering, Faculty of Innovation Engineering, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau 999078, China
Perry Ping Shum
Department of Electronic and Electrical Engineering, College of Engineering, Southern University of Science and Technology, 1088 Xueyuan Avenue, Shenzhen 518055, China
A fiber speckle sensor (FSS) based on a tapered multimode fiber (TMMF) has been developed to measure liquid analyte refractive index (RI) in this work. By the lateral and axial offset of input light into TMMF, several high-order modes are excited in TMMF, and the speckle pattern is spatially modulated, which affects an asymmetrical speckle pattern with a random intensity distribution at the output of TMMF. When the TMMF is immersed in the liquid analyte with RI variation, it influences the guided modes, as well as the mode interference, in TMMF. A digital image correlations method with zero-mean normalized cross-correlation coefficient is explored to digitize the speckle image differences, analyzing the RI variation. It is found that the lateral- and axial-offsets-induced speckle sensor can enhance the RI sensitivity from 6.41 to 19.52 RIU−1 compared to the one without offset. The developed TMMF speckle sensor shows an RI resolution of 5.84 × 10−5 over a linear response range of 1.3164 to 1.3588 at 1550 nm. The experimental results indicate the FSS provides a simple, efficient, and economic approach to RI sensing, which exhibits an enormous potential in the image-based ocean-sensing application.
