Simple interrogator for optical fiber-based white light Fabry-Perot interferometers.

Area of Science:

• Optics and Photonics
• Fiber Optic Sensing Technology
• Interferometry

Background:

• Optical fiber sensors offer advantages in harsh environments.
• Fabry-Perot interferometers (F-P) are widely used for sensing applications.
• Efficient signal interrogation is crucial for F-P sensor performance.

Purpose of the Study:

• To design a simple and cost-effective signal interrogator for optical fiber-based white light Fabry-Perot interferometers.
• To demonstrate the translation of spectral interference into a spatial interference pattern.
• To demodulate the Fabry-Perot cavity length using a straightforward algorithm.

Main Methods:

• Utilized a hardware setup comprising a fused silica wafer and a CCD camera.
• Developed a method to convert spectral interference from the F-P cavity into a spatial interference pattern.
• Implemented a simple demodulation algorithm for F-P cavity length extraction.

Main Results:

• Successfully designed and demonstrated a simple signal interrogator for white light F-P interferometers.
• Experimental validation using a fiber optic sensor with a sapphire wafer as the F-P cavity.
• Achieved demodulation of F-P cavity length through the developed spatial interference method.

Conclusions:

• The proposed interrogator design is effective for optical fiber-based white light F-P sensors.
• The simple hardware and algorithm offer a practical solution for F-P cavity length measurement.
• This approach provides a cost-effective alternative for fiber optic sensing systems.