Departamento de Física Aplicada, Instituto de Ciencia de los Materiales, Universidad de Valencia, Burjassot 46100, Spain.
Sensors (Basel). 2013 Aug 23;13(9):11260-70. doi: 10.3390/s130911260.
We report an easy-to-build, compact, and low-cost optical fiber refractive index sensor. It consists of a single fiber loop whose transmission spectra exhibit a series of notches produced by the resonant coupling between the fundamental mode and the cladding modes in a uniformly bent fiber. The wavelength of the notches, distributed in a wavelength span from 1,400 to 1,700 nm, can be tuned by adjusting the diameter of the fiber loop and are sensitive to refractive index changes of the external medium. Sensitivities of 170 and 800 nm per refractive index unit for water solutions and for the refractive index interval 1.40-1.442, respectively, are demonstrated. We estimate a long range resolution of 3 × 10(-4) and a short range resolution of 2 × 10(-5) for water solutions.
我们报道了一种易于构建、紧凑且低成本的光纤折射率传感器。它由一个单光纤环组成，其传输光谱显示出一系列由于在均匀弯曲光纤中基模和包层模之间的共振耦合产生的陷波。陷波的波长分布在 1400 到 1700nm 的波长范围内，可以通过调整光纤环的直径来调节，并且对外界介质折射率的变化敏感。对于水溶液，灵敏度分别为 170nm/RIU 和 800nm/RIU，对于折射率范围 1.40-1.442，灵敏度分别为 800nm/RIU 和 170nm/RIU。我们估计对于水溶液的长程分辨率为 3×10(-4)，短程分辨率为 2×10(-5)。
