Dual-polarization plasmonic metasurface for nonlinear optics

A plasmonic metasurface for the enhancement of nonlinear optical effects is proposed. The metasurface can simultaneously enhance perpendicularly polarized electric fields in the same volume. We illustrate application of the metasurface to the production of Terahertz radiation via the parametric process of difference frequency generation in (4) over bar 3m non-centro symmetric materials, e.g., GaAs, which has a large second-order nonlinear susceptibility. An enhancement over bulk of almost two orders of magnitude near the surface supports the use of the proposed structure for thin-film, surface-based, or chip-based nonlinear optical applications for several crystal classes. (C) 2015 Optical Society of America