All-Optical Modulation of Birefringence in Nonlinear All-Dielectric Metasurfaces

Steering the polarization of light at an ultrafast speed is a crucial functionality for a plethora of applications, including free-space optical links for high-speed information processing and recording. Nonlinear metamaterials have recently been developed for ultrafast manipulation of light polarization by all-optical means (i.e., upon excitation by a femtosecond control pulse). Here, we demonstrate strong birefringence features in a reconfigurable, anisotropic AlGaAs metasurface, achieving more than 90¡ rotation of the polarization ellipse at a few picosecond timescales.