An Exposed-Core Grapefruit Fibers Based Surface Plasmon Resonance Sensor

Area of Science:

• Optoelectronics
• Nanotechnology
• Chemical Sensing

Background:

• Microstructured optical fiber (MOF) sensors face challenges with air hole coating and analyte filling.
• Surface Plasmon Resonance (SPR) sensors offer high sensitivity but require optimized designs for real-world applications.

Purpose of the Study:

• To develop an improved SPR sensor addressing limitations of existing MOF-based sensors.
• To design an exposed-core grapefruit fiber (EC-GF) SPR sensor for enhanced analyte detection.

Main Methods:

• Fabrication of an EC-GF with a thin silver film coating on the exposed core.
• Utilized asymmetric coating to support dual-polarized resonance peaks (x- and y-polarized).
• Investigated sensor performance across a refractive index (RI) range of 1.33 to 1.42.

Main Results:

• The EC-GF SPR sensor demonstrated significantly higher peak loss for the x-polarized resonance peak.
• Achieved an exceptionally high wavelength sensitivity of 13,500 nm/RIU (refractive index unit).
• Analyzed the influence of silver layer thickness on overall sensing performance.

Conclusions:

• The EC-GF SPR sensor design effectively overcomes analyte filling and coating issues.
• The sensor exhibits superior sensitivity and potential for real-time, distributed refractive index sensing.
• This work provides a valuable reference for developing advanced SPR RI sensors.