Wednesday, July 17, 2019

Abstract-Direct space to time terahertz pulse shaping with nonlinear metasurfaces



Shay Keren-Zur and Tal Ellenbogen

Fig. 1. (a) Working principle of THz-DST pulse shaping with NLMS. A near infrared ultrashort pulse (NIR) excites a NLMS consisted of nonlinear meta-atom. Consequently, each meta-atom emits a single-cycle THz pulse as a point source. When measured in the far-field at an angle θ (i.e., collected and collimated after a slit), a train of single-cycle pulses is formed. The train of pulses is formed according to the spatial distribution of the meta-atoms on the meta-surface, and the nonlinear response of each emitter. (b) THz emission spectrum from a NLMS based on SRRs as was experimentally measured before [26]. (c) Temporal form of THz pulse emitted from the NLMS.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-15-20837

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.
© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

No comments: