Design of a High-Performance Micro Integrated Surface Plasmon Resonance Sensor Based on Silicon-On-Insulator Rib...

Area of Science:

• Photonics
• Nanotechnology
• Biomedical Engineering

Background:

• Surface Plasmon Resonance (SPR) is a label-free optical sensing technique.
• Traditional SPR systems often require bulky and expensive equipment like spectrometers.
• Miniaturization and integration of SPR sensing systems are highly desirable for practical applications.

Purpose of the Study:

• To propose and verify a micro integrated SPR biochemical sensor platform based on silicon-on-insulator (SOI) rib waveguides.
• To demonstrate the feasibility of wavelength interrogation for SPR sensor arrays, eliminating the need for external spectrometers.
• To achieve miniaturization and integration of the entire SPR sensing system.

Main Methods:

• Utilizing a silicon-on-insulator (SOI) rib waveguide with a large cross-section and a bimetallic configuration for SPR excitation.
• Employing the two-dimensional finite-difference time-domain (2D-FDTD) method for performance verification and parameter optimization.
• Composing an array of SPR sensors for wavelength interrogation of the output signal.

Main Results:

• A single bimetallic SPR sensor (3 nm Au/32 nm Al) demonstrated a high sensitivity of 3.968 × 10^4 nm/RIU and a detection accuracy of 14.7 μm^-1.
• A detection limit of 5.04 × 10^-7 RIU was achieved for a single SPR sensor.
• The SPR sensor array could detect refractive index variations as small as 1.14 × 10^-5 RIU with a relative power measurement accuracy of 0.01 dB.

Conclusions:

• The proposed SOI rib waveguide-based SPR sensor platform enables miniaturization and integration of biochemical sensing systems.
• Wavelength interrogation of SPR sensor arrays eliminates the need for spectrometers, facilitating compact and cost-effective devices.
• The demonstrated high sensitivity and detection accuracy highlight the potential of this platform for advanced biochemical sensing applications.