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Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-Pérot Etalon
Published on: February 3, 2023
Fabry-Perot refractometer based on an end-of-fiber polymer tip
O Frazão1, P Caldas, J L Santos
1INESC Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal. ofrazao@inescporto.pt
Optics Letters
|August 18, 2009
Summary
A novel polymer-tip fiber optic refractometer was developed for precise liquid analysis. This device achieves high resolution in measuring liquid refractive index using a micrometric Fabry-Perot interferometer.
Area of Science:
- Optoelectronics
- Fiber Optics
- Chemical Sensing
Background:
- Refractive index sensing is crucial for chemical analysis.
- Existing fiber optic sensors face limitations in resolution and fabrication.
Purpose of the Study:
- To propose and demonstrate a micrometric Fabry-Perot refractometer.
- To achieve high-resolution liquid refractive index measurements using a novel fiber tip.
Main Methods:
- Fabrication of a 36 µm polymer tip on a single-mode fiber using self-guiding photopolymerization.
- Implementation of two-wave interferometric operation using Fresnel reflection at fiber-polymer and fiber-end interfaces.
- Coherence addressing and heterodyne interrogation of the Fabry-Perot interferometer.
Main Results:
- Successful fabrication of a micrometric polymer tip on a fiber optic probe.
- Demonstration of two-wave interferometric operation for sensing.
- Achieved a liquid refractive index resolution of approximately 7.5x10⁻⁴.
Conclusions:
- The proposed end-of-fiber polymer tip refractometer offers a promising platform for sensitive liquid analysis.
- The fabrication method and interferometric interrogation are effective for high-resolution refractive index sensing.
