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Reflection intensity optical fiber sensors for the mid-infrared
Applied Optics
|February 20, 1997
Summary
Two new mid-infrared reflection sensors using chalcogenide glass fiber were developed. A single-fiber sensor achieved nearly 50% of the sensitivity of a double-fiber sensor for spectral measurements.
Area of Science:
- Optical sensing technologies
- Mid-infrared spectroscopy
- Materials science
Background:
- Chalcogenide glass fibers offer unique properties for mid-infrared (mid-IR) applications.
- Reflection intensity sensors are crucial for non-destructive material analysis.
- Existing sensor designs may have limitations in sensitivity or complexity.
Purpose of the Study:
- To demonstrate two novel reflection intensity sensors for the mid-IR region.
- To evaluate the performance of single-fiber and double-fiber sensor configurations.
- To develop a theoretical model for sensor characterization.
Main Methods:
- Fabrication of double-fiber and single-fiber reflection sensors using chalcogenide glass fiber.
- Integration of sensors with a Fourier-transform infrared (FTIR) spectrometer using nonimaging concentrators.
- Measurement of absorption spectra for polymer coatings and paper.
- Development and application of a theoretical model for signal-to-background ratio analysis.
Main Results:
- Demonstration of two distinct reflection sensor designs: a double-fiber sensor with a waveguide and a single-fiber sensor with contact couplers.
- Successful coupling of sensors to an FTIR spectrometer for spectral measurements.
- Application of a theoretical model to derive sensor sensitivity from experimental data.
- The single-fiber reflection sensor with a symmetric coupler exhibited approximately 50% of the absorption peak heights compared to the double-fiber sensor.
Conclusions:
- Both developed reflection sensors are viable for mid-IR spectral measurements.
- The single-fiber sensor offers a potentially simpler alternative, though with reduced sensitivity compared to the double-fiber design.
- The theoretical model effectively aids in understanding and quantifying sensor performance characteristics.
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