title: An Ultrasensitive Long-Period Fiber Grating-Based Refractive Index Sensor with Long Wavelengths.
abstract: The response of a novel long-period fiber grating (LPFG) with a period of 180 µm to a surrounding refractive index (RI) was investigated. The results displayed that, with the increase in RI of the surrounding media of cladding glass in the grating region, the resonant peak located at 1336.4 nm in the transmission spectrum gradually shifts towards a shorter wavelength, while the resonant peak located at 1618 nm gradually shifted towards a longer wavelength. Moreover, the resonant peak at 1618 nm is much more sensitive to the surrounding RI than that of the one at 1336.4 nm. Compared with the conventional LPFG and other types of wavelength-interrogated RI sensors, such as ring resonators, surface plasmon resonance sensors, and Fabry-Perot interferometric sensors, this novel LPFG possesses a higher sensitivity, which achieved 10,792.45 nm/RIU (RI unit) over a RI range of 1.4436-1.4489.
authors.affiliation: Key Biosensor Laboratory of Shandong Province, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China. liqs06@mails.jlu.edu.cn.
authors.forename: Qiu-Shun
authors.initials: QS
authors.lastname: Li
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. xulin_zhang@jlu.edu.cn.
authors.forename: Xu-Lin
authors.initials: XL
authors.lastname: Zhang
authors.affiliation: Key Biosensor Laboratory of Shandong Province, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China. shijg@sdas.org.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Shi
authors.affiliation: CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China. xd789@mail.ustc.edu.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Xiang
authors.affiliation: Key Biosensor Laboratory of Shandong Province, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China. zhengl@sdas.org.
authors.forename: Lan
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Key Biosensor Laboratory of Shandong Province, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China. swdz2@sdas.org.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Biosensor Laboratory of Shandong Province, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China. swdz@sdas.org.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Yang
authors.affiliation: Key Biosensor Laboratory of Shandong Province, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China. shenghua@sdas.org.
authors.forename: Dong
authors.initials: D
authors.lastname: Feng
authors.affiliation: CAS Key Laboratory of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China. wenfeidong@sibet.ac.cn.
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Dong
keywords: long wavelength; long-period fiber grating; refractive index; sensor; transmission spectrum