Ultra-Abrupt Tapered Fiber Mach-Zehnder Interferometer Sensors

Sensors

Benye Li²  Lan Jiang²  Sumei Wang²  Lanying Zhou²  Hai Xiao¹ 

[1] Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA; E-Mail:;School of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081, China; E-Mails:

关键词: fiber sensors;    refractive index;    Mach-Zehnder interferometer;    zeolite coating;   

DOI  :  10.3390/s110605729

来源: mdpi

【 摘 要 】

A fiber inline Mach-Zehnder interferometer (MZI) consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method. By fusion-splicing, the taper diameter-length ratio is around 1:1, which is much greater than those (1:10) made by stretching. The proposed fabrication method is very low cost, 1/20–1/50 of those of LPFG pair MZI sensors. The fabricated MZIs are applied to measure refractive index, temperature and rotation angle changes. The temperature sensitivity of the MZI at a length of 30 mm is 0.061 nm/°C from 30–350 °C. The proposed MZI is also used to measure rotation angles ranging from 0° to 0.55°; the sensitivity is 54.98 nm/°. The refractive index sensitivity is improved by 3–5 fold by fabricating an inline micro–trench on the fiber cladding using a femtosecond laser. Acetone vapor of 50 ppm in N₂ is tested by the MZI sensor coated with MFI–type zeolite thin film. The proposed MZI sensors are capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.