Microwave seminar | 29 June 2020

Nonlinear parametric process due to time-varying modulation can be found in systems of different scales, ranging from the energy-level splitting of trapped cold atoms, Raman scattering of vibrational molecules, and Brillouin scattering due to optoacoustic coupling, to the amplitude and frequency modulation of radio signals and the microDoppler effect widely employed in radar sensing. Introducing the extra degree of freedom -- time-varying modulation into metasurfaces could bring in functionalities unprecedented in conventional linear or tunable metasurfaces. In this seminar, I will demonstrate some interesting potentials of time-varying metasurfaces, including achieving dynamic and arbitrary tuning of the different degrees of freedom of parametric waves, and enhancing the radar stealth capability of an object by creating a broadband spectral camouflage.