Accumulation-layer hybridized surface plasmon polaritions at an ITO/LiNbO₃ interface

Area of Science:

• Materials Science
• Optics
• Condensed Matter Physics

Background:

• Highly lossy metals hinder practical applications in plasmonics.
• Electrostatic modification offers a route to low-loss plasmonic structures.
• Surface plasmon polaritons (SPPs) are crucial for nanoscale light manipulation.

Purpose of the Study:

• To demonstrate a novel low-loss structure supporting surface plasmon polaritons (SPPs).
• To theoretically and experimentally investigate the hybridized SPP support in an indium-tin-oxide (ITO)/lithium niobate (LN) system.
• To address the lack of theoretical treatment for sub-nanometer interlayers and anisotropic substrates in such structures.

Main Methods:

• Pairing a highly polar lithium niobate (LN) slab with a nonpolar indium-tin-oxide (ITO) thin film.
• Utilizing electrostatic screening to modify a sub-nanometer ITO layer for visible SPP support.
• Developing a hybridized SPP supporting picture for the ITO/LN system.
• Experimental verification using 2D diffraction patterns from gratings with mixed polarization laser beams.

Main Results:

• A sub-nanometer ITO layer on LN was successfully modified to support visible SPPs.
• The experimental 2D diffraction patterns closely matched the theoretical hybridized SPP model.
• The ITO/LN platform demonstrated effective support for surface plasmon polaritons.
• Parasitic scattering of surface waves was shown to be potentially suppressible.

Conclusions:

• The demonstrated ITO/LN system provides a promising platform for low-loss plasmonic devices.
• This work advances the understanding of SPP propagation in complex material systems.
• The findings pave the way for designing advanced hybridized SPP-based devices with enhanced performance.