Quasi-TPPs/Fano resonance systems based on an MDM waveguide structure and its sensing application

Area of Science:

• Photonics and Plasmonics
• Nanophotonics
• Optical Sensing

Background:

• Quasi-Tamm plasmon polaritons (TPPs) are surface electromagnetic modes.
• Fano resonance arises from interference between continuum and discrete states.
• Metal-dielectric-metal (MDM) waveguides are key structures in plasmonics.

Purpose of the Study:

• To propose and investigate quasi-TPPs/Fano resonance systems in MDM waveguides.
• To develop a simplified fabrication method for photonic devices.
• To evaluate the sensing performance of the proposed Fano resonance system.

Main Methods:

• Utilizing a metal plasmonic Bragg reflector (PBR) as a dielectric photonic crystal.
• Exciting quasi-TPPs via an Ag baffle and PBR within an MDM waveguide.
• Constructing a side-coupled resonator system for Fano resonance generation.

Main Results:

• Achieved quasi-TPPs excitation by meeting phase-matching conditions.
• Demonstrated Fano resonance through interference of continuum and discrete states.
• Obtained a high sensitivity of 1500 nm/RIU and a figure of merit of 4.08×10^5.

Conclusions:

• The proposed MDM waveguide structure enables efficient quasi-TPPs and Fano resonance.
• The open PBR design simplifies analyte interaction for sensing.
• The system shows significant potential for high-performance optical sensing applications.