解涛 杨志 王文军 吴宇 刘涛

摘  要：针对非本征F-P干涉仪式光纤声压传感器中的声压敏感薄膜性能提升，设计并制备了不同厚度和不同增敏环数的声压敏感薄膜结构。对不同声压敏感薄膜感知声压的性能进行测试。结果表明：声压敏感薄膜的厚度越薄，其声压灵敏度越大，对比400 nm厚度和1 000 nm厚度的声压敏感薄膜，发现在相同声压的声波作用下，前者的输出电压比后者大一个数量级。此外，增加增敏环数可以有效地释放应力，降低薄膜的刚性，使得声压传感器的性能有所提升。

关键词：微光电子机械系统;F-P干涉;光纤传感;声压传感器;增敏结构

中图分类号：TP212      文献标识码：A 文章编号：2096-4706（2021）02-0035-03

Abstract：In order to improve the performance of acoustic pressure sensitive film in extrinsic F-P interferometric fiber optic acoustic pressure sensor，the structures of acoustic pressure sensitive films with different thickness and different number of sensitizing rings were designed and fabricated. The performance of different sound pressure sensitive films was tested. The results showed that the thinner the thickness of the sound pressure sensitive film was，the greater the sound pressure sensitivity was. Compared with the sound pressure sensitive film with 400 nm thickness and 1 000 nm thickness，it was found that the output voltage of the former is one order of magnitude larger than that of the latter under the same sound pressure. In addition，increasing the number of sensitizing rings could effectively relieve the stress，reduce the rigidity of the film and improve the performance of the sound pressure sensor.

Keywords：MOEMS;F-P interference;optical fiber sensing;acoustic pressure sensor;sensitization configuration

0  引  言

基于非本征法珀干涉仪（Extrinsic Fabry-Perot Interfero- meter，EFPI）式光纤声压传感器需要构建两个反射面来形成F-P干涉，膜片式的敏感结构由于其方便制备，灵敏度高等特点常常与光纤端面构成F-P干涉腔。外界声压信号作用在敏感膜片上，发生微小的形变，这会引起F-P干涉腔腔长的变化，从而引起干涉光谱的波动，通过检测光谱波动来检测还原外界声波的相关信息。敏感膜片的制备方式很多，其中MEMS加工工艺以其加工精度高、设计灵活、一致性高、易批量化生产等显著优势成为研究的热点。MEMS加工工艺是以硅材料作为基础材料，所以加工的膜片敏感结构材料多数为硅、氮化硅或者氧化硅等。在MEMS加工工艺中，氧化硅薄膜通常采用热氧化和化学气相淀积（Chemical Vapor Deposition，CVD）的方法制备成膜，氮化硅薄膜也可以利用CVD工艺制作，而硅膜多数是采用干法刻蚀或者湿法腐蚀的方法制备得到，因此上述这些材料由于其多种兼容的制备工艺方法被广泛用作敏感膜片材料[1-3]。……