Abstract
A highly sensitive strain sensor based on a novel fiber in line Mach-Zehnder interferometer (MZI) was demonstrated experimentally. The MZI was realized by splicing a section of photonic crystal fiber (PCF) with the same length of thin core fiber (TCF) between two single mode fibers (SMFs). The fringe visibility of MZI can reach as high as 20 dB in air. In particular, the strain sensitivity of −1.95 pm/με was achieved within a range from 0 to 4000 με. Furthermore, the strain properties of different length of MZI was investigated. It was found that the sensitivity was weekly dependent on the length of MZI. The strain sensitivities corresponding to the MZI with 35 mm PCF, 40 mm PCF and 45 mm PCF at 1550 nm band were −1.78 pm/με, −1.73 pm/με and −1.63 pm/με, respectively. Additionally, the sensor has advantages of simple fabrication, compact size and high sensitivity as well as good fringe visibility.
Highlights
Optical fiber sensors has been widely used to monitor some parameters in sensing fields, such as temperature [1], refractive index [2], magnetic field [3], humidity [4], strain [5], which is due to their unique advantages of compact size, high resolution and immunity to electromagnetic interference [6,7].Among them, strain has played a critical role in the application of health inspection of bridges and buildings
Various strain sensors based on fiber Bragg gratings [10], long period fiber gratings [11], Fabry-Perot interferometer [12], Sagnac loop [13], Mach-Zehnder interferometer [14,15] and photonic crystal fiber (PCF) interferometer [16,17,18,19,20,21] have been proposed and demonstrated
We proposed a novel strain sensor based on Mach-Zehnder interferometer (MZI) with thin core fiber (TCF)-PCF structure, which was formed by splicing a piece of TCF with the same length of PCF between two single mode fibers (SMFs)
Summary
Optical fiber sensors has been widely used to monitor some parameters in sensing fields, such as temperature [1], refractive index [2], magnetic field [3], humidity [4], strain [5], which is due to their unique advantages of compact size, high resolution and immunity to electromagnetic interference [6,7]. In 2008, Choi [22] reported a new PCF-MZI structure with a high sensitivity of −1.8 pm/με within range from 0 to 2200 με. The strain sensitivity was about 1.7 pm/με, which was slightly smaller than that of our proposed MZI, but it has a big advantage of its capability to high temperatures up to 1000 ◦ C as well as larger measurement range up to 3800 με. We proposed a novel strain sensor based on MZI with TCF-PCF structure, which was formed by splicing a piece of TCF with the same length of PCF between two SMFs. The fusion point was more robot than that of up-tapered joint or collapsed fusion region, which making the sensor having merits of good mechanical strength and low fusion lost. The dependence of the stain sensitivity on the length of MZI was investigated experimentally
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
