Microfluidic assistant beat-frequency interferometer based on a single-hole-infiltrated dual-mode microstructured...

Area of Science:

• Optics and Photonics
• Fiber Optics
• Microfluidics

Background:

• Microstructured optical fibers (MOFs) offer unique light-guiding properties.
• Dual-mode MOFs (DM-MOFs) support multiple optical modes, enabling interferometric applications.
• Microfluidic integration with optical fibers allows for sensing in confined fluidic environments.

Purpose of the Study:

• To propose and demonstrate a microfluidic beat-frequency interferometer.
• To investigate the performance of a dual-mode microstructured optical fiber (DM-MOF) based sensor.
• To achieve simultaneous dual-parameter measurement (temperature and axial force).

Main Methods:

• Fabrication of a beat-frequency interferometer by inserting a fluid-filled DM-MOF into single-mode fibers with core-offset.
• Analysis of mode-mismatch induced interferences in the transmission spectrum.
• Experimental investigation of the sensor's response to temperature and axial force variations.

Main Results:

• Observed mode-mismatch interferences with distinct high-frequency dips and a low-frequency envelope.
• Demonstrated that infiltrated liquid enhances the sensitivity of the envelope to temperature and axial force.
• Achieved simultaneous sensitivities of -959.22 pm/°C for the envelope and -3.14 nm/N for the dips.

Conclusions:

• The proposed microfluidic beat-frequency interferometer based on DM-MOF is effective for dual-parameter sensing.
• The design allows for independent measurement of temperature and axial force with high sensitivity.
• This compact structure offers a promising platform for advanced optical sensing applications.