Highly sensitive surface plasmon resonance refractive index sensor comprising micro-grooved single-mode fibers

Area of Science:

• Optoelectronics
• Nanotechnology
• Chemical Sensing

Background:

• Surface plasmon resonance (SPR) is a powerful phenomenon with diverse applications in optical fiber sensing.
• Existing SPR-based sensors face challenges in structural stability and efficient energy transfer.
• Developing robust and sensitive optical fiber sensors is crucial for advanced analytical applications.

Purpose of the Study:

• To design and analyze a novel single-mode optical fiber refractive index sensor based on SPR.
• To enhance the sensor's mechanical strength and facilitate energy exchange between the fiber core and plasmonic modes.
• To evaluate the sensor's performance in detecting various liquid concentrations and refractive indices.

Main Methods:

• Fabrication of micro-grooves on a single-mode optical fiber to integrate a gold wire.
• Utilizing the finite element method (FEM) to analyze the influence of structural parameters on sensing properties.
• Experimental characterization of the sensor's response to sodium chloride and hemoglobin solutions.

Main Results:

• The sensor structure effectively couples light into plasmonic modes, improving mechanical stability.
• The sensor accurately detects sodium chloride solutions (120-360 g/L) and hemoglobin solutions (0-100 g/L).
• The sensor achieves high wavelength sensitivity (28,200 nm/RIU) for refractive index detection in the range of 1.33-1.41.

Conclusions:

• The designed SPR optical fiber sensor offers high sensitivity and mechanical robustness.
• The sensor demonstrates significant potential for quantitative analysis in biosensing and chemical detection.
• The integrated micro-groove structure is key to the sensor's enhanced performance and applicability.