title: Ultra-abrupt tapered fiber Mach-Zehnder interferometer sensors.
abstract: 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 N(2) 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.
authors.affiliation: School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China. libenye@bit.edu.cn
authors.forename: Benye
authors.initials: B
authors.lastname: Li
authors.forename: Lan
authors.initials: L
authors.lastname: Jiang
authors.forename: Sumei
authors.initials: S
authors.lastname: Wang
authors.forename: Lanying
authors.initials: L
authors.lastname: Zhou
authors.forename: Hai
authors.initials: H
authors.lastname: Xiao
authors.forename: Hai-Lung
authors.initials: HL
authors.lastname: Tsai
mesh_terms: D000465:Algorithms; D004566:Electrodes; D004784:Environmental Monitoring; D004867:Equipment Design; D005336:Fiber Optic Technology; D005740:Gases; D007368:Interferometry / Q000295:instrumentation* / Q000379:methods*; D007834:Lasers; D015233:Models, Statistical; D055100:Optical Fibers; D011634:Public Health; D012031:Refractometry / Q000295:instrumentation / Q000379:methods; D013696:Temperature; D017641:Zeolites / Q000737:chemistry
chemical_list: D005740:Gases; D017641:Zeolites