Sequeira Filipa, Duarte Daniel, Bilro Lúcia, Rudnitskaya Alisa, Pesavento Maria, Zeni Luigi, Cennamo Nunzio
Instituto de Telecomunicações, 3810-193 Aveiro, Portugal.
CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
Sensors (Basel). 2016 Dec 13;16(12):2119. doi: 10.3390/s16122119.
We report the optimization of the length of a D-shaped plastic optical fiber (POF) sensor for refractive index (RI) sensing from a numerical and experimental point of view. The sensing principle is based on total internal reflection (TIR). POFs with 1 mm in diameter were embedded in grooves, realized in planar supports with different lengths, and polished to remove the cladding and part of the core. All D-shaped POF sensors were tested using aqueous medium with different refractive indices (from 1.332 to 1.471) through intensity-based configuration. Results showed two different responses. Considering the refractive index (RI) range (1.33-1.39), the sensitivity and the resolution of the sensor were strongly dependent on the sensing region length. The highest sensitivity (resolution of 6.48 × 10 refractive index units, RIU) was obtained with 6 cm sensing length. In the RI range (1.41-1.47), the length of the sensing region was not a critical aspect to obtain the best resolution. These results enable the application of this optical platform for chemical and biochemical evanescent field sensing. The sensor production procedure is very simple, fast, and low-cost.
我们从数值和实验的角度报告了用于折射率（RI）传感的D形塑料光纤（POF）传感器长度的优化。传感原理基于全内反射（TIR）。将直径为1毫米的POF嵌入在不同长度的平面支撑体中制成的凹槽中，并进行抛光以去除包层和部分纤芯。所有D形POF传感器均通过基于强度的配置，使用具有不同折射率（从1.332到1.471）的水性介质进行测试。结果显示出两种不同的响应。考虑到折射率（RI）范围（1.33 - 1.39），传感器的灵敏度和分辨率强烈依赖于传感区域的长度。在传感长度为6厘米时获得了最高灵敏度（分辨率为6.48×10折射率单位，RIU）。在RI范围（1.41 - 1.47）内，传感区域的长度对于获得最佳分辨率不是关键因素。这些结果使得该光学平台能够应用于化学和生化倏逝场传感。该传感器的生产过程非常简单、快速且成本低廉。
