1. Optimization of Mach–Zehnder interferometer with cascaded up-tapers and application for curvature sensing.
- Author
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Xia, Feng, Zhao, Yong, and Chen, Mao-qing
- Subjects
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INTERFEROMETERS , *CURVATURE , *DETECTORS , *SHEAR strength , *SINGLE-mode optical fibers - Abstract
All-fiber Mach-Zehnder interferometers (MZIs) working as curvature sensors have been attracting increasing attention. However, previously reported MZI-based curvature sensors with offset or abrupt-taper structures suffer from weak mechanical strength and low curvature sensitivity. In this letter, a robust and highly-sensitive MZI-based curvature sensor formed by cascading two up-tapers in a single mode fiber (SMF) is proposed and experimentally demonstrated. By optimizing structural parameters of the MZI both in simulation and in experiment, a high quality interference spectrum with a maximum extinction ratio (ER) of around 20 dB is obtained, which is crucial in curvature sensing with spectrum intensity variation and interference dip identifiability being considered. Experimental results show that a high curvature sensitivity of −35.41 nm/m −1 is obtained in the range of 0.6846 m −1 – 1.0606 m −1 , which is 2.4 times higher than that of the interferometer with single-mode-multimode-single-mode (SMS) structure. The two up-tapers, featured by great mechanical strength, are fabricated by only fusion pushing together a whole SMF without cleaving procedure, contributing to excellent repeatability and consistency in the sensor fabrication process. Such an all-fiber sensor exhibits advantages of simple configuration, ease of fabrication, excellent mechanical strength, low cost, and high curvature sensitivity. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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