Development and stability analysis of an S-tapered optical fiber-based sensor structure

Area of Science:

• Fiber Optic Sensors
• Biomedical Sensing
• Nanophotonics

Background:

• S-tapered fiber (STF) structures are fabricated using conventional single-mode fiber.
• Reproducibility of STF fabrication is confirmed via diameter distribution analysis.

Purpose of the Study:

• To investigate the sensitivity of STF structures with varying diameters (40, 60, and 80 µm) to external refractive index changes.
• To evaluate the potential of the optimized STF structure for glucose concentration detection.

Main Methods:

• Fabrication of three STF structures with diameters of 40, 60, and 80 µm.
• Analysis of transmitted intensities and evanescent wave generation for each diameter.
• Testing the 40 µm STF sensor with varying concentrations of glucose solutions.

Main Results:

• The 40 µm diameter STF exhibited greater evanescent wave production compared to larger diameters.
• This STF structure demonstrated higher sensitivity to external refractive index variations.
• The 40 µm STF successfully detected different concentrations of glucose solutions.

Conclusions:

• The S-tapered fiber with a 40 µm diameter is highly sensitive to refractive index changes.
• This optimized STF structure shows significant potential for developing highly sensitive fiber optic sensors, particularly for glucose monitoring.