基于U型光纤中瑞利散射光谱探测的分布式折射率传感技术研究(特邀)

Distributed Refractive Index Sensing Based on U-bent Fiber through Spectral Detection of Rayleigh Backscattering(Invited)

折射率是材料的重要参数,对于折射率的检测和测量,已广泛应用在化学分析、环境保护和医疗卫生等诸多领域。其中,弯曲(U型)光纤是实现折射率传感的最简单结构,利用光纤的U型弯曲损耗可以受到弯曲光纤外部环境影响的基本原理,结合普通单模光纤高柔韧性不易折断等优点,提出了一种基于U型光纤中瑞利散射光谱探测的高灵敏度、结构简单和价格低廉的分布式折射率传感方案。当弯曲直径为0.7 cm时,在1.333 0~1.377 3的折射率测量范围内,其灵敏度达到42.57 nm/RIU的最佳值,并呈现良好的线性传感响应,使得医用等一次性廉价折射率传感探头的使用和普及成为可能。

Refractive index is an important parameter of materials.In many fields such as chemical analysis,environmental protection and medical health,the detection and measurement of refractive index have been widely used.Among them,bending or called U-shaped optical fiber is the simplest structure to achieve refractive index sensing,using the basic principle that the U-shaped bending loss of optical fiber can be affected by the external en⁃vironment of bending optical fiber,combined with the advantages of ordinary single-mode fiber,which has high flex⁃ibility and hard to break,etc.A high sensing sensitivity,simple structure and low cost distributed refractive index sensing scheme based on Rayleigh scattering spectrum detection in U-shaped fiber is proposed.When the bending diameter is 0.7 cm,the sensing sensitivity reaches the maximum value of 42.57 nm/RIU in the refractive index mea⁃surement range of 1.3330~1.3773,and presents a good linear sensing response,which makes the application and popularization of disposable cheap refractive index sensing probes such as medical devices possible.