论文标题
基于光学毛细管的干涉传感器，用于检测气体折射率
Optical capillary-based interferometric sensor for detection of gas refractive index
论文作者
论文摘要
在本文中，我们报告了一种基于毛细管的M-Z干涉仪，可用于精确检测气态样品折射率的变化。这种感应机制非常简单。毛细管的覆层和核心模式通过分别将相干激光束耦合到毛细管覆层和核心，同时激发。当从核心干扰覆层传播的光传播的光中，将生成干涉图。填充核心的空气折射率的变化导致核心和覆层模式之间的相位差异变化，从而改变了干扰条纹。使用光电二极管和狭窄的缝隙，我们可以分析边缘移位。发现传感器的分辨率为1*10-8 RIU，这与先前文献中报道的其他干涉量传感器获得的最高分辨率相当。最后，我们还分析了传感器的温度交叉灵敏度。我们的传感器的优点包括非常低的成本，高灵敏度，直接的感应机制和易于制造。
In this paper, we report a capillary-based M-Z interferometer that could be used for precise detection of variations in refractive indices of gaseous samples. This sensing mechanism is quite straightforward. Cladding and core modes of a capillary are simultaneously excited by coupling coherent laser beams to the capillary cladding and core, respectively. Interferogram would be generated as the light transmitted from the core interferes with the light transmitted from the cladding. Variations in refractive index of the air filling the core lead to variations in phase difference between the core and cladding modes, thus shifting the interference fringes. Using a photodiode together with a narrow slit, we could analyze the fringe shifts. The resolution of the sensor was found to be 1*10-8 RIU, that is comparable to the highest resolution obtained by other interferometric sensors reported in previous literatures. Finally, we also analyze the temperature cross sensitivity of the sensor. The advantages of our sensor include very low cost, high sensitivity, straightforward sensing mechanism, and ease of fabrication.
