We present a method for the generation of THz pulses with tailored temporal shape from nonlinear metasurfaces. The method is based on single-cycle THz emission by the metasurface inclusions. We show that the spatial amplitude and phase structure of the nonlinear response is mapped to the temporal shape of pulses emitted at certain angles. We specifically show a method for reconstruction of desired pulses, generation of few-cycles pulses with tailored carrier-envelope and all-optical control over the pulse shape by the pump pulse characteristics. In addition we use geometric phase to obtain further control over the local amplitude, phase and polarization of the THz waves.

UNMET NEED
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 while avoiding phononic interactions or phase mismatch considerations, and potentially obtain larger THz bandwidths. 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.
OUR SOLUTION
The engineering of the metasurface emitter, enables to obtain unprecedented control of the spatiotemporal properties of the emitted THz wave packets. Our results place nonlinear metasurface as a new promising tool for generating application-tailored THz fields with controlled spatial and temporal characteristics.

APPLICATIONS
• Medical imaging
• Security
• Scientific use and imaging
• Material inspection
• Communication
• Manufacturing

INTELLECTUAL PROPERTY
PCT/IL2021/050376, WO 2021205434

REFERENCES 
Generation of spatiotemporally tailored terahertz wavepackets by nonlinear metasurfaces – https://www.nature.com/article…