Microstructured optical fiber refractive index sensor.

Area of Science:

• Optics and Photonics
• Materials Science
• Chemical Sensing

Background:

• Microstructured optical fibers (MOFs) offer unique light-matter interaction properties.
• Refractive index sensing is crucial for various applications, including environmental monitoring and chemical analysis.
• Existing sensors often face trade-offs between sensitivity and measurement range.

Purpose of the Study:

• To design and demonstrate a dual-core microstructured optical fiber for fluid refractive index sensing.
• To achieve both a large measurement range and high sensitivity in a single sensing device.
• To investigate methods for enhancing sensor sensitivity through selective filling.

Main Methods:

• Fabrication of a dual-core microstructured optical fiber.
• Utilizing the exponential dependence of intercore coupling on the analyte's refractive index.
• Employing selective filling of the fiber's microstructure with the fluid analyte.

Main Results:

• The dual-core fiber demonstrated effective refractive index sensing of fluids.
• The device achieved both a large sensing range and high sensitivity.
• Selective filling of the microstructure increased the sensor's sensitivity by approximately one order of magnitude.

Conclusions:

• Dual-core MOFs provide a versatile platform for high-performance refractive index sensing.
• The proposed sensing mechanism allows for simultaneous optimization of range and sensitivity.
• Selective filling is a viable strategy to boost sensor sensitivity for demanding applications.