Tatel Gerard, Bao Xiaoyi
Physics Department, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
Sensors (Basel). 2022 Jul 16;22(14):5328. doi: 10.3390/s22145328.
A compact fiber ultrasound-sensing device comprising a commercially available Barium Titanate (BaTiO) glass microsphere coupled to an open cavity off-core Fabry-Perot interferometer (FPI) fiber sensor is proposed and demonstrated. The open cavity is fabricated through splicing two segments of a single mode fiber (SMF-28) at lateral offsets. The lateral offset is matched to the radius of the microsphere to maximize their coupling and allow for an increased sensing response. Furthermore, the microsphere can be moved along the open-air cavity to allow for tuning of the reflection spectrum. The multiple passes of the FPI enabled by the high refractive index microsphere results in a 40 dB enhancement of finesse and achieves broadband ultrasound sensing from 0.1-45.6 MHz driven via a piezoelectric transducer (PZT) centered at 3.7 MHz. The goal is to achieve frequency detection in the MHz range using a repeatable, cost effective, and easy to fabricate FPI sensor design.
本文提出并展示了一种紧凑的光纤超声传感装置，该装置包括一个与开腔离芯法布里 - 珀罗干涉仪（FPI）光纤传感器耦合的市售钛酸钡（BaTiO）玻璃微球。通过在横向偏移处拼接两段单模光纤（SMF - 28）来制造开腔。横向偏移与微球半径相匹配，以最大化它们之间的耦合，并实现增强的传感响应。此外，可以沿着开腔移动微球，以调整反射光谱。由高折射率微球实现的FPI多次反射导致精细度提高40 dB，并通过以3.7 MHz为中心的压电换能器（PZT）驱动，实现了0.1 - 45.6 MHz的宽带超声传感。目标是使用可重复、经济高效且易于制造的FPI传感器设计，在MHz范围内实现频率检测。
