Analysis of a highly sensitive flat fiber plasmonic refractive index sensor

Area of Science:

• Photonics and Sensing
• Materials Science
• Nanotechnology

Background:

• Surface Plasmon Resonance (SPR) sensors are crucial for detecting changes in refractive index.
• Traditional photonic crystal fiber (PCF) sensors face fabrication challenges and limitations in sensitivity.
• Developing efficient and high-resolution refractive index sensors is essential for biochemical analysis.

Purpose of the Study:

• To propose and analyze an efficient double-layered flat fiber (DLFF) plasmonic sensor.
• To achieve high resolution and linearity in refractive index (RI) measurements.
• To explore the potential of DLFF for advanced biochemical sensing applications.

Main Methods:

• Utilizing a thin gold film as the SPR active material, protected by a titanium dioxide layer on a DLFF.
• Employing the finite element method to analyze structural parameters and layer thicknesses.
• Investigating wavelength and amplitude interrogation techniques in the near-infrared region.

Main Results:

• Achieved an average wavelength sensitivity of 12172 nm/RIU and a resolution of 8.21×10^-6 RIU in the high RI range (1.445–1.490).
• Demonstrated amplitude sensitivity of 2910 RIU^-1 with a resolution of 3.44×10^-6 RIU.
• The DLFF sensor offers a simpler fabrication process compared to traditional PCF SPR sensors.

Conclusions:

• The proposed DLFF plasmonic sensor exhibits excellent performance metrics, including high sensitivity and resolution.
• The sensor design is a potential candidate for developing advanced biochemical sensors and portable devices.
• DLFF technology offers a promising alternative for fabricating high-performance optical sensors.