Optical fiber strain sensor using fiber resonator based on frequency comb Vernier spectroscopy

Area of Science:

• Optoelectronics
• Fiber Optic Sensors
• Spectroscopy

Background:

• Fiber ring resonators are sensitive to external perturbations.
• Frequency comb Vernier spectroscopy offers high-resolution spectral analysis.
• Accurate strain sensing is crucial in various engineering applications.

Purpose of the Study:

• To propose and demonstrate a novel optical fiber strain sensor.
• To leverage frequency comb Vernier spectroscopy for enhanced strain detection.
• To investigate the sensor's linearity and sensitivity characteristics.

Main Methods:

• A fiber ring resonator was fabricated and integrated with a passively mode-locked fiber laser to generate a frequency comb.
• Strain was applied to the optical fiber within the resonator.
• Transmission spectra were analyzed to determine strain-induced wavelength shifts.

Main Results:

• The sensor demonstrated a strong linear relationship between displacement and the inverse of wavelength spacing (R² = 0.9989).
• High sensitivities exceeding 40 pm/με were achieved within a 0 to 10 με strain range.
• Sensitivity was shown to be scalable with the length of the fiber ring resonator.

Conclusions:

• The proposed frequency comb Vernier spectroscopy-based fiber ring resonator sensor is a highly sensitive and linear method for optical fiber strain sensing.
• The sensor's performance can be further optimized by increasing the resonator's fiber length.
• This technology holds promise for advanced strain monitoring applications.