Hybrid Graphene-Plasmonic Gratings to Achieve Enhanced Nonlinear Effects at Terahertz Frequencies

The demonstration of enhanced nonlinear optical effects at terahertz frequencies is important for the development of reconfigurable planar THz devices. However, high input intensities are usually required to efficiently excite nonlinear optical effects in ultrathin structures---an acute problem here, as high-power THz sources are not available. This work presents a class of ultrathin, nonlinear, hybrid planar THz devices based on graphene-covered plasmonic gratings. These devices exhibit very large nonlinear responses to low input power, and are expected to be useful for THz nonlinear spectroscopy, noninvasive subwavelength imaging, and communication applications.