Optical fiber Fabry-Perot interferometer based on phase-shifting technique and birefringence crystals

Area of Science:

• Optoelectronics
• Interferometry
• Optical Sensing

Background:

• Fabry-Perot interferometers are sensitive optical devices.
• Phase ambiguity can limit measurement accuracy.
• Birefringence crystals offer unique optical properties.

Purpose of the Study:

• To propose and demonstrate a novel optical fiber Fabry-Perot interferometer.
• To utilize phase-shifting techniques and birefringence for enhanced signal demodulation.
• To evaluate the sensor's performance in terms of stability and accuracy.

Main Methods:

• Fabrication of an optical fiber Fabry-Perot sensor.
• Employing four birefringence crystals to generate quadrature phase-shifted signals.
• Implementing phase-shifting demodulation techniques.
• Experimental validation using two distinct interferometer configurations.

Main Results:

• The proposed interferometer effectively avoids phase ambiguity.
• Achieved high stability for optical sensing applications.
• Demonstrated superior performance compared to a calibration microphone at 21 kHz and 40 kHz sinusoidal sonic signals.
• The normalized standard deviation was significantly lower than the calibration microphone.

Conclusions:

• The developed optical fiber Fabry-Perot interferometer offers a stable and accurate sensing solution.
• The use of birefringence crystals and phase-shifting techniques enhances measurement reliability.
• The sensor is suitable for applications requiring a large measurement range and high precision.