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Polarization-dependent curvature sensor based on an in-fiber Mach-Zehnder interferometer with a difference arithmetic
Changyu Shen1, Chuan Zhong, Yang You
1Institute of Optoelectronic Technology, China Jiliang University, Hangzhou, 310018, China. shenchangyu@cjlu.edu.cn
Optics Express
|July 10, 2012
Summary
A novel fiber optic curvature sensor using a polarization-dependent in-fiber Mach-Zehnder interferometer (MZI) detects bending by analyzing interference fringe visibility. This sensor offers high sensitivity and reduced cross-sensitivity to temperature and power fluctuations.
Area of Science:
- Optical Fiber Sensors
- Interferometry
- Fiber Optic Sensing Technology
Background:
- Fiber optic sensors are crucial for measuring physical parameters.
- Mach-Zehnder interferometers (MZIs) offer high sensitivity but can be susceptible to environmental factors.
- Developing robust and sensitive curvature sensors is essential for various applications.
Purpose of the Study:
- To propose and demonstrate a novel polarization-dependent in-fiber Mach-Zehnder interferometer (MZI) for curvature sensing.
- To investigate the sensor's performance, including sensitivity and range.
- To evaluate the effectiveness of a difference arithmetic demodulation method in mitigating cross-sensitivity.
Main Methods:
- Fabrication of an in-fiber MZI by core-offset fusion splicing of polarization-maintaining fiber (PMF) between single-mode fibers (SMFs).
- Utilizing two orthogonal polarization modes within the PMF for independent interference pattern generation.
- Measuring curvature by detecting changes in fringe visibility of the interference patterns.
- Implementing a difference arithmetic demodulation method to compensate for light source power fluctuations and temperature variations.
Main Results:
- The proposed sensor achieved a maximal sensitivity of -0.882 dB/m(-1) within a curvature measurement range of 0.1 to 0.35 m(-1).
- The difference arithmetic demodulation method significantly reduced temperature-curvature cross-sensitivity by 94%.
- Light source power fluctuation effects were reduced by 91% using the implemented demodulation method.
Conclusions:
- The polarization-dependent in-fiber MZI is a viable and sensitive platform for curvature sensing.
- The difference arithmetic demodulation technique effectively enhances the sensor's robustness against environmental disturbances and power fluctuations.
- This sensor technology shows promise for accurate and reliable curvature measurement in demanding applications.
