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Writing Bragg Gratings in Multicore Fibers
Published on: April 20, 2016
Fiber refractometer based on a fiber Bragg grating and single-mode-multimode-single-mode fiber structure.
Qiang Wu1, Yuliya Semenova, Binbin Yan
1Photonics Research Center, School of Electronic and Communications Engineering, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland. qiang.wu@dit.ie
Optics Letters
|June 21, 2011
Summary
A novel fiber optic sensor using a single-mode-multimode-single-mode (SMS) structure and fiber Bragg grating achieves high sensitivity for refractive index (RI) measurement. This sensor offers a practical method for determining RI by analyzing wavelength shifts.
Area of Science:
- Optoelectronics
- Fiber Optics
- Sensing Technology
Background:
- Refractive index (RI) sensing is crucial for various applications, including chemical analysis and biomedical diagnostics.
- Traditional RI sensors often face limitations in sensitivity, selectivity, or operational complexity.
- Fiber optic sensors offer advantages like remote sensing, immunity to electromagnetic interference, and miniaturization.
Purpose of the Study:
- To demonstrate a novel fiber optic sensor for refractive index (RI) measurement.
- To investigate the sensing mechanism based on a single-mode-multimode-single-mode (SMS) fiber structure combined with a fiber Bragg grating (FBG).
- To evaluate the sensitivity and performance of the proposed RI sensor.
Main Methods:
- Fabrication of a hybrid fiber structure comprising SMS fiber followed by an FBG.
- Excitation of cladding modes within the output single-mode fiber (SMF) by the multimode fiber.
- Recoupling of reflected cladding Bragg wavelength to the input SMF core for detection.
- Measurement of relative Bragg wavelength shifts between core and cladding modes to determine RI.
Main Results:
- The proposed sensor successfully utilized the SMS structure and FBG to excite and recouple cladding modes.
- A linear relationship between Bragg wavelength shift and RI was observed.
- The sensor achieved a maximum sensitivity of 7.33 nm/RIU within the RI range of 1.324 to 1.439.
- The experimental results validated the effectiveness of the novel fiber structure for RI sensing.
Conclusions:
- The demonstrated SMS-FBG fiber optic sensor provides a sensitive and effective platform for RI measurement.
- The sensor's design allows for precise RI determination by analyzing core and cladding mode wavelength shifts.
- This technology holds potential for applications requiring accurate and real-time RI monitoring.
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