Investigation of broadband terahertz generation from metasurface

Abstract

The nonlinear metamaterials have been shown to provide nonlinear properties with high nonlinear conversion efficiency and in a myriad of light manipulation. Here we study terahertz generation from nonlinear metasurface consisting of single layer nanoscale split-ring resonator array. The terahertz generation due to optical rectification by the second-order nonlinearity of the split-ring resonator is investigated by a time-domain implementation of the hydrodynamic model for electron dynamics in metal. The results show that the nonlinear metasurface enables us to generate broadband terahertz radiation and free from quasi-phase-matching conditions. The proposed scheme provides a new concept of broadband THz source and designing nonlinear plasmonic metamaterials.

Generation of spatiotemporally tailored terahertz wavepackets by nonlinear metasurfaces

“…In conclusion, we demonstrate a novel method for generation of structured single-cycle THz wavepackets from engineered NLMS. Such NLMS can replace conventional nonlinear crystals in THz generation systems to provide new functionalities without sacrificing efficiency, avoid phononic interactions or phase mismatch considerations, and potentially obtain larger THz bandwidths 25,26 . This unprecedented capability, which overcomes several limitations of conventional THz generation and manipulation schemes, opens the door for advanced THz technologies, such as beam multiplexing, structured-light THz imaging, single-shot spectroscopy, THz holography, particle manipulation, and structured THz light–matter interactions.…”

“…Few recent works studied the possibility to generate THz radiation from optically excited plasmonic metasurfaces. Initially, broadband THz generation by ponderomotive acceleration of photoelectrons was reported 22,23 , and more recently broadband THz generation by optical rectification (OR) on nonlinear metasurfaces (NLMSs) was also demonstrated and studied 24–26 . In the latter mechanism, the generation efficiency that was demonstrated from ultrathin metasurface was comparable and even exceeded that of OR in conventional sub-mm thick THz crystals, such as ZnTe and GaP.…”

A Novel High-Order Symplectic Compact FDTD Schemes for Optical Waveguide Simulation

“…Further analysis of the normalized propagation constant κ and the resolution factor R have critical role to play in minimizing numerical global phase errors  . A comprehensive comparisons of global phase error between SC-FDTD(4, 4) and C-S24 [5], [7] at the same time step t  max for different R and κ is shown in Table II. It be clearly seen that the error of SC-FDTD(4, 4) algorithm is far below that of the C-S24 algorithm at any value κ and R. Meanwhile, the excessively high resolution factors R are needed near the limiting value of κ approaches unity of the C-S24 algorithm.…”

“…Further analysis of the normalized propagation constant κ and the resolution factor R have critical role to play in minimizing numerical global phase errors  . A comprehensive comparisons of global phase error between SC-FDTD(4, 4) and C-S24[5],[7] at the same time step t…”

THz-Photonics Transceivers By All-Dielectric Phonon-Polariton Nonlinear Nanoantennas

“…Despite the fact that THz sources are still lacking in some spectral regions, photoinduced THz generation is today obtained by various mechanisms, including optical rectification and photoemission [12][13][14][15][16][17] . Recently, THz generation by optical rectification in plasmonic Split-Ring Resonators (SRRs) has been reported 18,19 ; the THz signal is produced from nanoscale SRRs by exciting magnetic-dipole modes in the infrared regime. A thorough study of THz pulse generation using a 40 nm thin metasurface based on plasmonic SRRs excited with a laser oscillator emitting nanojoule femtosecond pulses has been reported in 20 , measuring a conversion efficiency as high as that of a 0.1 mm thick ZnTe crystal.…”