High sensitivity cascaded helical-core fiber SPR sensors  

作　　者：Xianbin Wang Hongchang Deng Libo Yuan 王宪彬;邓洪昌;苑立波(Key Laboratory of In-fiber Integrated Optics,Ministry of Education,Harbin Engineering University,Harbin 150001,China;Photonics Research Center,School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]Key Laboratory of In-fiber Integrated Optics,Ministry of Education,Harbin Engineering University,Harbin 150001,China [2]Photonics Research Center,School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guilin 541004,China

出　　处：《Chinese Optics Letters》2021年第9期7-12,共6页中国光学快报（英文版）

基　　金：supported by the National Key R&D Program of China (No. 2017YFB0405501);the National Natural Science Foundation of China (Nos. 61705050, 61675052, 61965005, 61975038, and 61827819);the Guangxi Project (Nos. 2018AD19081 and 2018AA20001)

摘　　要：The distributed optical fiber surface plasmon resonance(SPR)sensors have attracted wide attention in biosensing and chemical sensing applications.However,due to the limitation of their sensing structure,it is difficult to adjust their res-onant wavelength and sensitivity.Here,novel and flexible cascaded helical-core fiber[HCF)SPR sensors are proposed theoretically and experimentally for distributed sensing applications.It is shown that the resonant wavelength and sensitivity of the sensors can be conveniently controlled by adjusting the twist pitch of the helical core.A high sensitivity of 11,180 nm/RIU for refractive-index measurement ranging from 1.355 to 1.365 is realized experimentally when the twist pitch of the helical core is 1.5 mm.It is worth noting that the sensitivity can be further improved by reducing the twist pitch.For example,the sensitivity of the sensor with a twist pitch of 1.4 mm can theoretically exceed 20,000 nm/RIU.This work opens up a new way to implement multi-parameter or distributed measurement,especially to establish sensing networks integrated in a single-core fiber or a multi-core fiber.

关 键 词：helical-core fiber surface plasmon resonance distributed optical fiber sensor whispering gallery modes 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]