High-sensitivity transverse-load and high-temperature sensor based on the cascaded Vernier effect

Area of Science:

• Fiber Optic Sensors
• Optical Interferometry
• Material Science

Background:

• Traditional sensors often lack sensitivity or the ability to measure multiple parameters simultaneously.
• The Vernier effect offers a method to enhance sensor sensitivity through optical interference.
• Developing robust sensors for harsh environments (high temperature, mechanical stress) is crucial.

Purpose of the Study:

• To demonstrate a novel fiber optic sensor capable of measuring both transverse load and high temperature.
• To leverage the cascaded Vernier effect for enhanced sensitivity in both measurement types.
• To explore the flexible and combined use of different fiber optic components.

Main Methods:

• Fabrication of a sensor system comprising two cascaded Fabry-Perot interferometers using hollow-core fiber (HCF) and polarization-maintaining photonic crystal fiber (PM-PCF).
• Connection of the interferometers via a 1-meter single-mode fiber section.
• Utilizing the cascaded Vernier effect to amplify the optical response to external stimuli.

Main Results:

• The transverse-load sensor sensitivity was enhanced by 7.7 times, reaching 5.84 nm/N.
• High-temperature sensitivity was increased by 5.5 and 5.9 times, achieving -0.0689 nm/°C (50-400°C) and -0.1038 nm/°C (400-900°C).
• Demonstrated the modularity and flexible combination of HCF and PM-PCF cavities.

Conclusions:

• The developed sensor effectively utilizes the cascaded Vernier effect for enhanced transverse-load and high-temperature sensing.
• The sensor exhibits significantly improved sensitivity and potential for flexible configurations.
• This novel sensor design holds considerable promise for advanced sensing applications requiring high performance in demanding conditions.