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

To circumvent the hindrance to broad practical applications associated with uses of highly lossy metals in plasmonics, electrostatic modification-based low-loss structures are conceived and demonstrated in supporting surface plasmon polaritions (SPPs). Pairing a highly polar LiNbO3 (LN) slab with a nonpolar indium-tin-oxide (ITO) thin film, a subnanometer ITO layer was modified into visible SPPs supportive owing to electrostatic screening; yet a theoretical treatment of a sandwiched structure with a sub-nanometer interlayer and an anisotropic substrate is still missing. In this Letter, a hybridized SPP supporting picture was drawn in the ITO/LN system, which agrees well with the 2D diffraction patterns observed out of phase gratings written with two coherent laser beams either of pure-extraordinary, pure-ordinary, or mixed polarizations. This platform of ITO/LN is promising in designing hybridized SPP-based devices in which the parasitic scattering of surface waves may be suppressed greatly.