中文摘要：

将单锥微纳光纤模式干涉仪和石墨烯相结合,实现了一种高灵敏度的光纤式氨气传感器,其利用石墨烯的特异性吸附效应及微纳光纤结构的高灵敏度传感特性,通过检测干涉光谱的漂移量实现了对氨气浓度微弱变化的检测.对不同组传感器进行了对比分析,结果表明当光纤直径为3.4μm时最大检测灵敏度为10.8 pm/ppm,与文献中采用其它光纤结构所报道的结果相比几乎提高了一倍。该传感器具有结构简单、易于实现及灵敏度高等优点,在危害气体浓度报警和人体健康检测等领域有潜在的应用前景。

英文摘要：

A fiber ammonia gas sensor with high sensitivity is realized by combining single taper-basea microfiber modal interferometer with graphene film. It uses grapheme＇s specific absorption property to ammonia and high sensitivity sensing characteristics of microfiber structure and the detection of weak changes of ammonia concentration is realized by detecting the shift of interference spectrum. Comparison and analysis are carried out among different groups of sensors. Results show that when the fiber diameter is 3：4 μm, the maximum detection sensitivity is 10.8 pm/ppm, which is almost doubled compared to the results of other reported fiber structures. The proposed sensor has the advantages of simple structure, easy implementation and high sensitivity and it has potential application prospect in the fields of harmful gases concentration alarm and human health detection etc.