A gas pressure sensor, based on a phase-shifted fiber Bragg grating (PS-FBG) modulated by a hollow cavity, is proposed and demonstrated in this Letter. The device was fabricated by fusing a hollow-core fiber (HCF) between two single-mode fibers (SMFs) exhibiting FBGs that were inscribed using line-by-line femtosecond (fs) laser etching. A pair of micro-channels were drilled orthogonally into the HCF using an fs laser to allow the argon gas to get in and out freely. Such a sensor exposes a high spectrum finesse, e.g., a $Q$-factor of $\sim\! 7302$, which can be improved by increasing the grating pitch quantity. Furthermore, a high gas pressure sensitivity of 1.22 nm/Mpa is obtained, corresponding the improved sensor with a grating pitch quantity of 300 and a hollow cavity length of 88.3 µm. In addition, the device exhibited a low temperature sensitivity of 8.92 pm/°C.

中文翻译：

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空心腔调制的相移光纤布拉格光栅用于测量气压

提出并演示了一种气压传感器，该气压传感器基于通过中空腔调制的相移光纤布拉格光栅（PS-FBG）进行了演示。该设备是通过将空心光纤（HCF）融合在两个显示出FBG的单模光纤（SMF）之间的方法制成的，这些光纤通过逐行飞秒（fs）激光蚀刻来刻划。使用fs激光将一对微通道正交钻入HCF，以使氩气自由进出。这样的传感器暴露出高频谱精细度，例如，$ Q $因子$ \ sim \ !！7302 $，这可以通过增加光栅间距来改善。此外，获得了1.22 nm / Mpa的高气压灵敏度，对应于改进的传感器，其栅距为300，空腔长度为88.3 µm。此外，该器件还具有8.92 pm /°C的低温灵敏度。