Dual-cavity interferometric wavelength-shift detection for in-fiber Bragg grating sensors.

Area of Science:

• Optics and Photonics
• Sensor Technology
• Fiber Optic Sensing

Background:

• In-fiber Bragg grating (FBG) sensors are widely used for measuring physical parameters.
• Enhancing the unambiguous measurement range of FBG sensors is crucial for many applications.
• Current methods for extending the range can be complex or compromise resolution.

Purpose of the Study:

• To introduce and demonstrate a dual-cavity interrogation method for FBG sensors.
• To enhance the unambiguous measurement range of FBG sensors.
• To achieve high-resolution interferometric wavelength-shift detection.

Main Methods:

• Utilizing a stepped interferometric wavelength scanner with dual cavity lengths.
• Generating two sets of interference fringes.
• Interrogating an in-fiber Bragg grating temperature sensor using a stepped Michelson wavelength scanner.

Main Results:

• The dual-cavity method successfully enhances the unambiguous measurement range.
• High-resolution interferometric wavelength-shift detection is achieved.
• Demonstrated feasibility with a practical FBG temperature sensor.

Conclusions:

• The dual-cavity interrogation technique offers a promising approach to extend FBG sensor capabilities.
• This method provides a viable solution for applications requiring a wider measurement range without sacrificing resolution.
• Further research can explore its application in various FBG sensing scenarios.