Discrete plasmonic Talbot effect in finite metal waveguide arrays

Area of Science:

• Photonics and Nanophotonics
• Plasmonics

Background:

• Surface plasmon polaritons (SPPs) enable light manipulation at the nanoscale.
• Metal waveguide arrays (MWGAs) are crucial for integrated plasmonic circuits.

Purpose of the Study:

• To introduce supermode theory for analyzing SPP propagation in finite MWGAs.
• To quantitatively determine excited supermode coefficients and explain field distributions.
• To achieve and analyze the discrete plasmonic Talbot effect in MWGAs.

Main Methods:

• Application of supermode theory to SPP propagation.
• Quantitative analysis of supermode coefficients.
• Superposition of excited SPP supermodes to explain field intensity.
• Adjustment of input field intensities for Talbot effect.
• Comparison with conventional dielectric waveguides.
• Verification using the finite difference time-domain (FDTD) method.

Main Results:

• Supermode theory successfully describes SPP propagation in finite MWGAs.
• Excited supermode coefficients are quantitatively determined.
• Field intensity distributions are explained by supermode superposition.
• A discrete plasmonic Talbot effect is achieved in finite MWGAs.
• The input field period condition differs from dielectric waveguides.

Conclusions:

• Supermode theory provides a robust framework for understanding SPP dynamics in MWGAs.
• The discrete plasmonic Talbot effect is demonstrated and controllable in MWGAs.
• Findings offer insights for designing advanced plasmonic devices and circuits.