Dual-mode surface-plasmon sensor based on bimetallic film

Area of Science:

• Plasmonics
• Nanotechnology
• Optical Sensors

Background:

• Surface plasmons (SPs) are crucial for optical sensing applications.
• Bimetallic nanostructures offer tunable plasmonic properties.
• Existing SP sensors face challenges in accuracy and cross-sensitivity.

Purpose of the Study:

• To propose and theoretically investigate a novel silver-gold bimetallic film for SP excitation.
• To demonstrate the potential for simultaneous excitation of two SPs with equal propagation constants.
• To explore the use of this structure as an effective self-reference sensor.

Main Methods:

• Theoretical analysis of a two-layered silver-gold metallic film.
• Modeling of simultaneous surface plasmon excitation at different wavelengths.
• Investigation of plasmon manipulation and sensor performance optimization.

Main Results:

• Successful theoretical demonstration of exciting two SPs with equal propagation constants.
• Identification of unique opportunities for plasmon manipulation using the bimetallic film.
• Validation of the structure's potential for optimizing sensor accuracy and cross-sensitivity.

Conclusions:

• The proposed silver-gold bimetallic film offers a promising platform for advanced plasmonic sensing.
• The structure facilitates self-referenced sensing in a wavelength-interrogated design.
• This approach enhances sensor performance by enabling precise control over plasmon behavior.