A Dual-Wavelength Fiber Laser Sensor with Temperature and Strain Discrimination

Area of Science:

• Photonics and Optical Engineering
• Fiber Optic Sensing
• Laser Technology

Background:

• Dual-wavelength fiber lasers are crucial for advanced sensing applications.
• Developing stable and equalized dual-emission lasers remains a challenge.
• Artificial reflectors offer potential for novel fiber laser designs.

Purpose of the Study:

• To present a dual-wavelength C-band erbium-doped fiber laser.
• To utilize an artificial backscatter reflector for laser enhancement.
• To investigate the laser's performance for simultaneous strain and temperature sensing.

Main Methods:

• Fabrication of a 32 mm fiber-based artificial backscatter reflector using femtosecond laser direct writing.
• Construction of a dual-wavelength erbium-doped fiber laser system.
• Characterization of laser parameters including wavelength, signal-to-noise ratio, power difference, stability, and threshold pump power.
• Evaluation of the laser's sensing capabilities for strain and temperature.

Main Results:

• Achieved dual-wavelength emission centered at 1527.7 nm and 1530.81 nm with an optical signal-to-noise ratio over 46 dB at 150 mW pump power.
• Demonstrated high channel equalization with a power difference of only 0.02 dB.
• Observed low output power (0.3 dB) and central wavelength (0.01 nm) instability.
• Measured a threshold pump power of 40 mW.
• Successfully performed simultaneous strain and temperature measurements with sensitivities of 1 pm/με and 9.29 pm/°C, respectively.

Conclusions:

• The proposed dual-wavelength fiber laser, enhanced by an artificial backscatter reflector, exhibits excellent performance characteristics.
• The laser's high stability, equalization, and dual-emission capability make it suitable for advanced sensing applications.
• This technology enables the simultaneous and accurate measurement of strain and temperature using a single fiber optic system.