Opt Lett. 2023 Apr 15;48(8):1990-1993. doi: 10.1364/OL.488930.
A highly sensitive inline gas pressure sensor based on the hollow core Bragg fiber (HCBF) and harmonic Vernier effect (VE) is proposed and experimentally demonstrated. By sandwiching a segment of HCBF between the lead-in single-mode fiber (SMF) and the hollow core fiber (HCF), a cascaded Fabry-Perot interferometer is produced. The lengths of the HCBF and HCF are precisely optimized and controlled to generate the VE, achieving a high sensitivity of the sensor. Meanwhile, a digital signal processing (DSP) algorithm is proposed to research the mechanism of the VE envelope, thus providing an effective way to improve the sensor's dynamic range based on calibrating the order of the dip. Theoretical simulations are investigated and matched well with the experimental results. The proposed sensor exhibits a maximum gas pressure sensitivity of 150.02 nm/MPa with a low temperature cross talk of 0.00235 MPa/ C. All these advantages highlight the sensor's enormous potential for gas pressure monitoring under various extreme conditions.
提出并实验验证了一种基于空心芯布拉格光纤（HCBF）和谐 Vernier 效应（VE）的高灵敏度在线气压传感器。通过将一段 HCBF 夹在引入单模光纤（SMF）和空心光纤（HCF）之间，产生了级联法布里-珀罗干涉仪。精确优化和控制 HCBF 和 HCF 的长度以产生 VE，从而实现传感器的高灵敏度。同时，提出了一种数字信号处理（DSP）算法来研究 VE 包络的机制，从而为基于校准阶数的 dip 提供了一种提高传感器动态范围的有效方法。理论模拟进行了研究，并与实验结果吻合良好。所提出的传感器具有 150.02nm/MPa 的最大气压灵敏度，并且温度交叉干扰低至 0.00235MPa/℃。所有这些优势突出了该传感器在各种极端条件下进行气压监测的巨大潜力。
