An Enhanced Plastic Optical Fiber-Based Surface Plasmon Resonance Sensor with a Double-Sided Polished Structure

Area of Science:

• Photonics and Optical Sensors
• Materials Science

Background:

• Surface Plasmon Resonance (SPR) sensors offer high sensitivity for detecting refractive index changes.
• Plastic Optical Fibers (POFs) provide a cost-effective and flexible platform for sensor development.
• Existing POF-based SPR sensors face limitations in sensitivity and measurement range.

Purpose of the Study:

• To propose and demonstrate an enhanced POF-based SPR sensor using a double-sided polished structure.
• To improve the SPR excitation and enhance sensor performance, particularly for high refractive index measurements.
• To evaluate the sensitivity and potential applications of the novel sensor design.

Main Methods:

• Fabrication of a POF by symmetrically polishing two sides along the fiber axis.
• Deposition of gold (Au) film on both polished surfaces to enable dual-side SPR excitation.
• Simulation and experimental validation of the sensor's optical properties and performance.
• Measurement of sensitivity using liquids with a refractive index of 1.42.

Main Results:

• The double-sided polished POF structure successfully enhanced the SPR effect.
• Improved spectral visibility and reduced Full Width at Half Maximum (FWHM) were observed.
• A high sensitivity of 4284.8 nm/RIU was achieved for a refractive index of 1.42.
• The sensor demonstrated a larger measurement range and action area.

Conclusions:

• The proposed double-sided polished POF-based SPR sensor offers enhanced performance and ease of fabrication.
• The low-cost, high-sensitivity sensor has significant potential for applications in the oil industry and biochemical sensing.
• This design represents a promising advancement in optical fiber sensing technology.