Nonlinear metasurfaces have emerged as a powerful platform for terahertz (THz) frequency conversion, yet their performance is fundamentally limited by the weak nonlinearity of conventional noble-metal structures. Here, we demonstrate a graphene-based asymmetric double-split resonant rings metasurface that achieves record-high third-harmonic generation (THG) efficiency. By precisely controlling the geometric asymmetry of the graphene resonators, localized field enhancement is concentrated in 24% of the graphene area, generating an ultra-strong electron aggregation effect. Remarkably, the structure exhibits extreme polarization anisotropy: under y-polarized excitation (100 kW/cm2), the THG efficiency reaches 14.64% - a 100,000-fold enhancement over x-polarization performance. This giant polarization anisotropy stems from asymmetric geometry-induced dipole-quadrupole synergistic enhancement effect. The metasurface also maintains >7% THG efficiency across an ultra-wide ±45° angular range, demonstrating 50% greater angular tolerance than metal-based counterparts. Our findings establish a universal design rule linking geometric asymmetry to nonlinear response in 2D material metasurfaces, while providing a practical route toward chip-integrated THz wave converters for next-generation communication systems.
Peng et al. (Wed,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: