Yang Jing, Guan Chunying, Tian Peixuan, Yuan Tingting, Zhu Zheng, Li Ping, Shi Jinhui, Yang Jun, Yuan Libo
Opt Lett. 2017 Nov 1;42(21):4470-4473. doi: 10.1364/OL.42.004470.
We propose a novel and simple in-fiber refractive index sensor based on resonant coupling, constructed by a short section of single eccentric hole-assisted dual-core fiber (SEHADCF) spliced between two single-mode fibers. The coupling characteristics of the SEHADCF are calculated numerically. The strong resonant coupling occurs when the fundamental mode of the center core phase-matches to that of the suspended core in the air hole. The effective refractive index of the fundamental mode of the suspended core can be obviously changed by injecting solution into the air hole. The responses of the proposed devices to the refractive index and temperature are experimentally measured. The refractive index sensitivity is 627.5 nm/refractive index unit in the refractive index range of 1.335-1.385. The sensor without solution filling is insensitive to temperature in the range of 30-90°C. The proposed refractive index sensor has outstanding advantages, such as simple fabrication, good mechanical strength, and excellent microfluidic channel, and will be of importance in biological detection, chemical analysis, and environment monitoring.
我们提出了一种基于共振耦合的新型简单光纤折射率传感器，它由一段短的单偏心孔辅助双芯光纤（SEHADCF）拼接在两根单模光纤之间构成。对SEHADCF的耦合特性进行了数值计算。当中心纤芯的基模与气孔中悬浮纤芯的基模相位匹配时，会发生强烈的共振耦合。通过向气孔中注入溶液，可以明显改变悬浮纤芯基模的有效折射率。对所提出的器件对折射率和温度的响应进行了实验测量。在1.335 - 1.385的折射率范围内，折射率灵敏度为627.5 nm/折射率单位。未填充溶液的传感器在30 - 90°C范围内对温度不敏感。所提出的折射率传感器具有诸如制作简单、机械强度好和出色的微流体通道等突出优点，在生物检测、化学分析和环境监测中具有重要意义。
