Modelling nanofiber Mach-Zehnder interferometers for refractive index sensors

作者：Wu Pinghui; Sui Chenghua^*; Ye Biqing

来源：Journal of Modern Optics, 2009, 56(21): 2335-2339.

DOI：10.1080/09500340903414601

• silica nanofibre
• refractive index
• evanescent wave
• Mach-Zehnder interferometer
• sensitivity

In a single-mode silica nanofibre a large amount of the energy of the guided light is in the form of evanescent waves, making it possible to develop a novel sensing element with high sensitivity. Based on theoretical modelling, a highly-sensitive sensor employing a nanofibre-assembled Mach-Zehnder structure is suggested and investigated here. The sensor is used to measure the refractive indices of isopropyl alcohol (IPA) solutions of different concentrations. A phase shift of the guided mode, originating from the change of refractive index of the ambient medium, is obtained. In addition, the important parameters, including sensitivity and detection limit, are also estimated. The results show that Mach-Zehnder interferometric sensor based on nanofibres exhibits the capability of measuring an index variation of similar to 10(-6). Our simulations are helpful for studying and developing new miniaturised high-performance sensors with high sensitivity.

• 出版日期2009
• 单位浙江工业大学