Surface-plasmon-resonance-based fiber-optic refractive index sensor: sensitivity enhancement.

Area of Science:

• Photonics and Optics
• Materials Science
• Sensor Technology

Background:

• Surface Plasmon Resonance (SPR) sensors are crucial for refractive index sensing.
• Enhancing SPR sensor sensitivity and stability is an ongoing research challenge.
• Dielectric layers can modify SPR characteristics.

Purpose of the Study:

• To investigate the effect of a high-index dielectric layer (silicon) on SPR-based fiber-optic refractive index sensors.
• To optimize sensor sensitivity and durability through dielectric layer integration.
• To analyze the influence of silicon layer thickness on sensor performance.

Main Methods:

• Experimental study of SPR-based fiber-optic sensors.
• Utilizing wavelength interrogation method for analysis.
• Incorporating silver and gold as SPR active metals with a silicon dielectric layer.

Main Results:

• A redshift in resonance wavelength was observed with increasing refractive index.
• Sensor sensitivity increased with silicon layer thickness, up to approximately 10 nm.
• Increased electric field intensity at the silicon-sensing interface correlated with higher sensitivity.

Conclusions:

• The integration of a silicon dielectric layer significantly enhances the sensitivity of SPR-based fiber-optic refractive index sensors.
• Silicon layers offer tunable resonance wavelengths and improved metal layer protection, increasing sensor durability.
• Experimental findings align with theoretical models, validating the approach for advanced sensor design.