Arc-remodified long period fiber grating for monitoring absolute bending condition. (1st May 2022)

• Record Type: Journal Article
• Authors: Lu, Chupeng; Wang, Jiabin; Xu, Xian; Rui, Zeju; Xiang, Zihang; Yan, Qi; Geng, Tao; Yuan, Libo
• Is Part Of: Journal of optics. Volume 24:Number 5(2022)
• Publication Date: 2022-05-01
• Subjects: long period fiber grating -- arc-remodifying -- CO2 laser -- bending absolute condition; Optics -- Periodicals; 535.05
• DOI: 10.1088/2040-8986/ac5b4e
• Languages: English
• ISSNs: 2040-8978

Abstract

Abstract: In this paper, we propose an arc-remodified long period fiber grating (AR-LPFG) and introduce the ratios of shift-distance of two resonant dips (RSRDs) as a novel distinguishing index to monitor bending absolute condition which refers to detect the curvature and directions of fiber under a stationary status. The AR-LPFG is configured by arc-remodifying the LPFG that prepared from CO2 laser. The refractive index of the fiber is modulated again by the arc-remodification method which results in new resonant dips. Two orthogonal bending directions are distinguished by comparing the RSRDs, which are calculated to be 0.51 and 1.42 for 0° and 90°, respectively. Two opposite bending directions are distinguished by the opposite shift directions of two resonant dips. The stability and reliability of the novel distinguishing method are verified by a series of comparative experiments. The AR-LPFG still contains a conspicuous performance for bending variation sensing with a maximum sensitivity of 17.02 nm m −1 . The AR-LPFG, together with the orientation distinguishing index, can be widely applied at the fields that the bending relative variation or absolute condition need to be monitored.