Plasmonic CROWs for Tunable Dispersion and High Quality Cavity Modes.

Area of Science:

• Integrated Optics
• Plasmonics
• Nanophotonics

Background:

• Coupled resonator optical waveguides (CROWs) offer potential for integrated optics, enabling light slowing and enhanced optical phenomena.
• Localized surface plasmons (LSPs) in plasmonic nanoparticles provide subwavelength confinement and broad resonances.

Purpose of the Study:

• To design and investigate a compact plasmonic CROW by side-coupling plasmonic nanoparticles to a dielectric waveguide.
• To explore the tunability of dispersion, loss mechanisms, and robustness to disorder in this novel CROW design.

Main Methods:

• Utilized localized surface plasmons in a compact CROW architecture.
• Side-coupled plasmonic nanoparticles to a dielectric waveguide.
• Analyzed the central mode's dispersion and loss characteristics.

Main Results:

• Achieved a low-loss central mode with highly tunable dispersion, avoiding band-edge coupling issues.
• Demonstrated Fabry-Perot type resonances with high quality factors (thousands) in finite plasmonic CROWs.
• Showed the design's robustness to disorder, with tunable loss and outcoupling via geometric parameter variation.

Conclusions:

• The plasmonic CROW design minimizes loss while maintaining tunable dispersion, making it suitable for chip-integrated laser devices.
• This approach offers a promising platform for advanced linear and non-linear nanophotonics applications.
• The design's robustness to disorder enhances its practical applicability in integrated photonic circuits.