Plasmonic nanoarcs: a versatile platform with tunable localized surface plasmon resonances in octave intervals

Area of Science:

• Plasmonics
• Nanophotonics
• Infrared Spectroscopy

Background:

• Localized surface plasmon resonances (LSPRs) are crucial for nanophotonic applications.
• Metallic nanoarcs offer unique plasmonic properties due to their geometry.
• Controlling LSPR modes is essential for advanced optical devices.

Purpose of the Study:

• To demonstrate the tunability of longitudinal LSPRs in metallic nanoarcs.
• To establish relationships between nanoarc geometry and LSPR characteristics.
• To enable independent tuning of fundamental and second-order LSPRs for octave intervals.

Main Methods:

• Investigated metallic nanoarcs with varying geometric parameters.
• Analyzed the impact of mid-arc length on LSPR wavelength.
• Correlated nanoarc central angle with LSPR attenuation ratios.
• Utilized non-uniform arc-width profiles for independent resonance tuning.

Main Results:

• LSPR wavelength is tunable via mid-arc length.
• Nanoarc central angle governs the ratio of fundamental to second-order LSPR attenuation.
• Independent tuning of resonances to achieve octave intervals is demonstrated.
• Fundamental LSPR mode exhibits combined electric and magnetic dipole character.

Conclusions:

• Metallic nanoarcs provide tunable plasmonic resonances in the infrared.
• Geometric control allows for independent tuning of LSPR modes.
• Tunable plasmonic nanoarcs are promising building blocks for chiroptical and nonlinear optical devices.