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Published on: September 30, 2019
Highly sensitive bending sensor based on Er3+-doped DBR fiber laser.
Weisheng Liu1, Tuan Guo, Allan Chi-lun Wong
1Photonics Research Center, Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China. wsliu@coer.zju.edu.cn
Optics Express
|August 20, 2010
Summary
A novel Erbium-doped fiber laser sensor demonstrates highly sensitive bending measurement. Its low polarization beat frequency allows precise curvature detection, simplifying sensor systems for practical applications.
Area of Science:
- Optoelectronics
- Fiber Optics
- Sensor Technology
Background:
- Fiber lasers offer unique sensing capabilities.
- Distributed-Bragg-reflector (DBR) lasers provide stable operation.
- Polarization properties of fiber lasers can be exploited for sensing.
Purpose of the Study:
- To demonstrate a short cavity Erbium-doped (Er3+) DBR fiber laser for bending measurement.
- To investigate the sensitivity of the laser's polarization beat frequency to bending.
- To assess the sensor's performance regarding temperature sensitivity and cost-effectiveness.
Main Methods:
- Fabrication of a short cavity Er3+-doped DBR fiber laser.
- Experimental measurement of polarization beat frequency changes under varying bending curvatures.
- Theoretical analysis to validate experimental findings.
- Characterization of temperature sensitivity.
Main Results:
- The DBR fiber laser sensor exhibits high sensitivity to bending, detecting curvature changes as small as 1.8 x 10(-2) m(-1).
- Experimental and theoretical results for bending curvatures (0 to 58.8 m(-1)) show excellent agreement, with beat frequency changes from 18.6 MHz to 253 MHz.
- The sensor demonstrates low temperature sensitivity (-25.4 kHz/°C), negating the need for temperature compensation.
Conclusions:
- The developed Er3+-doped DBR fiber laser is a highly sensitive and robust optical bending sensor.
- Its low polarization beat frequency simplifies the demodulation scheme, enabling low-cost sensor systems.
- The sensor's insensitivity to temperature makes it suitable for various practical applications.
