Fiber ring laser based on MMF-PMFBG-MMF filter for three parameters sensing.

Area of Science:

• Optoelectronics
• Fiber Optics Sensing
• Laser Technology

Background:

• Fiber optic sensors offer high sensitivity and immunity to electromagnetic interference.
• Simultaneous multi-parameter sensing remains a challenge in fiber optic sensor development.
• Dual-wavelength fiber lasers provide a platform for advanced sensing capabilities.

Purpose of the Study:

• To propose and experimentally demonstrate a dual-wavelength fiber ring laser sensor.
• To achieve simultaneous measurement of axial strain, temperature, and refractive index (RI).
• To investigate the performance of a novel multimode fiber-polarization maintaining fiber Bragg grating-multimode fiber (MMF-PMFBG-MMF) filter.

Main Methods:

• A dual-wavelength fiber ring laser configuration was designed and built.
• A MMF-PMFBG-MMF filter was employed to ensure stable dual-wavelength lasing.
• Simultaneous sensing was achieved by monitoring wavelength shifts and output power variations.

Main Results:

• The fiber laser sensor demonstrated sensitivities of 1.16 × 10^-3nm/με for axial strain and 81.2dB/RIU for RI.
• Temperature sensitivities of 9.74 × 10^-3nm/°C and 9.2 × 10^-3nm/°C were measured for the two wavelengths.
• The proposed sensor successfully realized simultaneous axial strain, temperature, and RI measurements.

Conclusions:

• The developed dual-wavelength fiber laser sensor enables accurate and simultaneous measurement of multiple physical parameters.
• The MMF-PMFBG-MMF filter plays a crucial role in achieving stable dual-wavelength lasing and enabling selective sensing.
• This sensor technology holds potential for various applications requiring precise environmental monitoring.