We propose and demonstrate a cost-effective liquid refractive index (RI) sensor in polymer materials by employing a Mach-Zehnder interferometer (MZI) formed with the conventional strip waveguide. The proposed sensor can attain high sensitivity by choosing a suitable reference arm length to reduce optical path difference (OPD) between the two arms of the employed MZI. Our fabricated devices, which have the same sensing arm length of 7900 µm but different reference arm lengths of 7900.0, 7942.5, 7950.9, 7962.2, and 7969.5 µm, respectively, exhibit the maximum RI sensitivities of 33662.8 nm/RIU, and almost the same detection range (DR) of 0.0041 ± 0.0002 RIU.

中文翻译：

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基于常规聚合物条形波导的高性价比马赫曾德尔干涉仪液体折射率传感器

我们提出并证明了通过采用与常规条形波导一起形成的Mach-Zehnder干涉仪（MZI），在聚合物材料中具有成本效益的液体折射率（RI）传感器。所提出的传感器可以通过选择合适的参考臂长度来减小所用MZI的两个臂之间的光程差（OPD），从而获得高灵敏度。我们制造的设备具有相同的检测臂长度7900 µm，但具有不同的参考臂长度7900.0、7942.5、7950.9、7962.2和7969.5 µm，它们的最大RI灵敏度为33662.8 nm / RIU，并且检测几乎相同范围（DR）为0.0041±0.0002 RIU。