Compact fiber tip modal interferometer for high-temperature and transverse load measurements.

Area of Science:

• Optical Fiber Sensing
• Interferometry
• Modal Interferometry

Background:

• Fiber optic sensors are crucial for monitoring physical parameters in various environments.
• Modal interferometers offer unique sensing capabilities due to their sensitivity to external perturbations.
• Developing compact and robust fiber sensors is essential for practical applications, especially in harsh conditions.

Purpose of the Study:

• To demonstrate a compact fiber tip modal interferometer (FTMI) fabricated using a simple fusion splicing technique.
• To analyze the interference spectra of FTMI with varying sizes and profiles.
• To evaluate the FTMI's suitability for simultaneous high-temperature and transverse load sensing in harsh environments.

Main Methods:

• Fabrication of the FTMI through fiber tapering using a fusion splicer, creating a sensing area of approximately 310 μm.
• Analysis of interference spectra for fiber tips with different dimensions and profiles.
• Investigation of mechanical strength and high-temperature stability of the fabricated FTMI.

Main Results:

• A compact FTMI with a small effective sensing area (~310 μm) was successfully fabricated.
• The FTMI exhibits good mechanical strength and stability at high temperatures.
• Simultaneous monitoring of high-temperature and transverse load is achievable by selecting two distinct attenuation peaks.

Conclusions:

• The demonstrated FTMI offers a simple fabrication process and compact design.
• The device possesses robust mechanical properties and high-temperature stability, suitable for harsh environments.
• The FTMI is a promising candidate for simultaneous dual-parameter sensing (temperature and transverse load).