None sharp corner localized surface plasmons resonance based ultrathin metasurface single layer quarter wave plate

Area of Science:

• Nanophotonics
• Plasmonics
• Metamaterials

Background:

• Quarter wave plates are crucial optical components for controlling light polarization.
• Existing wave plates often suffer from limitations in thickness, bandwidth, or fabrication complexity.
• Localized surface plasmons (LSP) offer unique light-matter interaction possibilities at the nanoscale.

Purpose of the Study:

• To design and demonstrate a non-sharp-corner quarter wave plate (NCQW) with enhanced performance.
• To explore the use of silver (Ag) hollow elliptical ring arrays for plasmonic wave plate applications.
• To achieve precise control over the amplitude and phase of orthogonal light components.

Main Methods:

• Fabrication of an 8 nm thin film structured with Ag hollow elliptical ring arrays.
• Excitation of strong localized surface plasmons (LSP) resonances.
• Systematic manipulation of the hollow elliptical ring parameters.
• Characterization of transmitted amplitude and phase for orthogonal polarization components.

Main Results:

• Simultaneous achievement of a π/2 phase difference and an amplitude ratio of 1 at 834 nm wavelength.
• Observed optical transmission of 0.46 at the target wavelength.
• Demonstrated effective operation over an ultrawide wavelength band of 110 nm.
• Efficient excitation of LSP resonances confirmed.

Conclusions:

• The proposed NCQW offers an efficient method for exciting LSP resonances.
• This design provides a versatile platform for creating advanced wave plates.
• The NCQW shows significant potential for integration into nanophotonic devices and photonic systems.