Femtosecond pulse shaping with semiconductor Huygens' metasurfaces

Shaping of short laser pulses offers versatile applications in laser processing, quantum state encoding, ultrafast bio-chemical reactions, and optical communication. Optical metasurfaces have emerged as highly influential and versatile tools for exerting precise control over the properties of incident light. Dielectric Huygens' metasurfaces, in particular, possess the capability to finely tune phase while confining electric and magnetic modes within the resonators, thereby presenting additional prospects, including the exploration of nonlinear effects. In our study, we demonstrate pulse shaping at femtosecond time scale using spatially variant silicon Huygens' metasurfaces. We experimentally achieve control over pulse dynamics, demonstrating the transformation of a single Gaussian pulse into two pulses as well as into a temporally stretched pulse. The excellent agreement between the measured output pulses and our simulations demonstrates the capability of our metasurfaces to generate precise pulse shapes with femtosecond-level temporal resolution.