Yang J, Jiang L, Wang S, Li B, Wang M, Xiao H, Lu Y, Tsai H
Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, China.
Appl Opt. 2011 Oct 1;50(28):5503-7. doi: 10.1364/AO.50.005503.
A taper-based Mach-Zehnder interferometer (MZI) embedded in a thinned optical fiber is demonstrated as a highly sensitive refractive index (RI) sensor. A RI sensitivity of 2210.84 nm/RIU (refractive index unit) is obtained at the external RI of 1.40, which is ten times higher than that of normal taper- and long-period fiber grating (LPFG)-based sensors. The sensitivity can be further improved by decreasing the diameter of the thinned fiber and increasing the interferometer length of the MZI. The proposed MZIs have lower temperature sensitivities compared with normal fiber sensors, which is a desirable merit for RI sensors to reduce the cross sensitivity caused by thermal drift.
一种嵌入在细径光纤中的基于锥形的马赫-曾德尔干涉仪（MZI）被证明是一种高灵敏度的折射率（RI）传感器。在外部折射率为1.40时，获得了2210.84 nm/RIU（折射率单位）的RI灵敏度，这比普通基于锥形和长周期光纤光栅（LPFG）的传感器高出十倍。通过减小细径光纤的直径和增加MZI的干涉仪长度，可以进一步提高灵敏度。与普通光纤传感器相比，所提出的MZI具有更低的温度灵敏度，这对于RI传感器来说是一个理想的优点，可减少由热漂移引起的交叉灵敏度。
