Yang Yong, Zhang Xiaobei, Yang Lei, Yu Yang, Wang Zijie, Wang Tingyun
Opt Lett. 2021 Mar 1;46(5):1053-1056. doi: 10.1364/OL.419203.
We demonstrate an optical fiber displacement sensor based on the Vernier effect, consisting of a single-mode fiber (SMF) and a section of capillary with an internal movable microsphere freely controlled forward and backward by a half-taper. The antiresonance is inhibited to purify the reflectance spectra by optimizing the capillary length. The interference of three beams reflected from the splicing interface, front and rear surfaces of the microsphere, respectively, hence results in the Vernier effect due to combined cavities. By adjusting the distance between the splicing interface and front surface, an appropriate Vernier effect can significantly enhance the displacement sensitivity up to 344.8 pm/nm, with a subnanometer resolution of 0.058 nm. The proposed device has advantages such as simple fabrication process, compact size, and ultrahigh sensitivity, showing a great potential in displacement sensing applications.
我们展示了一种基于游标效应的光纤位移传感器，它由单模光纤（SMF）和一段毛细管组成，毛细管内部有一个可移动的微球，通过半锥度可自由前后控制。通过优化毛细管长度来抑制反共振，以纯化反射光谱。分别从微球的拼接界面、前表面和后表面反射的三束光的干涉，由于组合腔而产生游标效应。通过调整拼接界面与前表面之间的距离，适当的游标效应可将位移灵敏度显著提高至344.8 pm/nm，分辨率低至0.058 nm。所提出的器件具有制造工艺简单、尺寸紧凑和超高灵敏度等优点，在位移传感应用中显示出巨大潜力。
