Mie-Driven Ultrafast Faraday Rotation in Magnetophotonic Metasurfaces

Abstract

We report ultrafast Faraday rotation dynamics inside a single femtosecond pulse transmitted through a Mie-resonant semiconductor metasurface covered with a thin ferromagnetic film. Time-resolved cross-correlation measurements reveal intrapulse polarization rotation with a relative modulation of 55% over 500 fs at the wavelength of the merged magnetic and electric dipole Mie resonances. These results may be applicable to subpicosecond polarization state control in integrated optical nonreciprocal isolators, ultrafast modulators, sensors, and optical signal processing units.