Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, 07745 Jena, Germany.
INESC TEC and Department of Physics and Astronomy, Faculty of Sciences, University of Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
Sensors (Basel). 2019 Jan 22;19(3):453. doi: 10.3390/s19030453.
New miniaturized sensors for biological and medical applications must be adapted to the measuring environments and they should provide a high measurement resolution to sense small changes. The Vernier effect is an effective way of magnifying the sensitivity of a device, allowing for higher resolution sensing. We applied this concept to the development of a small-size optical fiber Fabry⁻Perot interferometer probe that presents more than 60-fold higher sensitivity to temperature than the normal Fabry⁻Perot interferometer without the Vernier effect. This enables the sensor to reach higher temperature resolutions. The silica Fabry⁻Perot interferometer is created by focused ion beam milling of the end of a tapered multimode fiber. Multiple Fabry⁻Perot interferometers with shifted frequencies are generated in the cavity due to the presence of multiple modes. The reflection spectrum shows two main components in the Fast Fourier transform that give rise to the Vernier effect. The superposition of these components presents an enhancement of sensitivity to temperature. The same effect is also obtained by monitoring the reflection spectrum node without any filtering. A temperature sensitivity of -654 pm/°C was obtained between 30 °C and 120 °C, with an experimental resolution of 0.14 °C. Stability measurements are also reported.
新型微型生物医学传感器必须适应测量环境，并且应提供高测量分辨率以感知微小变化。游标效应是放大设备灵敏度的有效方法，可实现更高分辨率的感应。我们将这一概念应用于小型光纤法布里-珀罗干涉仪探头的开发，该探头对温度的灵敏度比没有游标效应的普通法布里-珀罗干涉仪高 60 多倍。这使得传感器能够达到更高的温度分辨率。硅基法布里-珀罗干涉仪是通过对锥形多模光纤末端进行聚焦离子束铣削而制成的。由于存在多个模式，在腔中会产生多个具有不同频率的法布里-珀罗干涉仪。反射光谱在快速傅里叶变换中显示出两个主要分量，这导致了游标效应。这些分量的叠加提高了对温度的灵敏度。通过监测无任何滤波的反射光谱节点也可以获得相同的效果。在 30°C 至 120°C 之间，获得了-654 pm/°C 的温度灵敏度，实验分辨率为 0.14°C。还报告了稳定性测量结果。
