Yao Chenyu, Wang Qiang, Lin Yuechuan, Jin Wei, Xiao Limin, Gao Shoufei, Wang Yingying, Wang Pu, Ren Wei
Opt Lett. 2019 Aug 15;44(16):4048-4051. doi: 10.1364/OL.44.004048.
We demonstrate the first, to the best of our knowledge, photothermal carbon monoxide (CO) sensor using a hollow-core negative curvature fiber. The hollow-core fiber features a typical structure of one ring cladding containing eight nontouching capillaries to form a negative curvature core-surround. The photothermal effect in a 40-μm hollow core is induced by CO absorption at 2327 nm and detected by a Mach-Zehnder interferometer operating at 1533 nm. By using wavelength modulation spectroscopy, we achieve a normalized noise equivalent absorption coefficient of 4.4×10 cm WHz. As CO has a very slow vibrational-translational relaxation process, we enhance the photothermal signal by enhancing the relaxation with the water vapor additive.
据我们所知，我们首次展示了一种使用空心负曲率光纤的光热一氧化碳（CO）传感器。空心光纤具有典型的结构，即一个环形包层包含八个不接触的毛细管，以形成负曲率的纤芯包围结构。40μm空心纤芯中的光热效应由CO在2327nm处的吸收诱导，并由工作在1533nm的马赫-曾德尔干涉仪检测。通过使用波长调制光谱，我们实现了4.4×10⁻⁹cm⁻¹W⁻¹Hz⁻¹/²的归一化噪声等效吸收系数。由于CO具有非常缓慢的振动-平动弛豫过程，我们通过添加水蒸气增强弛豫来增强光热信号。
