ИСТИНА

All-dielectric resonant nanostructures have been extensively studied during the last years leading to establishment of the new rapidly developing research field. Most attraction these systems achieve due to many possible applications ranging from ultrathin optical devices such as metalenses or holograms to completely new topological structures. However their functionalities often limited by the passive response defined by the designed configuration of the system. Investigation of the actively tunable devices controllable by the external stimulus can lead to creation of new elements for all-dielectric nanophotonics. In this work we study both numerically and experimentally an all-optical modulation of the scattering properties of both single nanoantennas and metasurfaces made of GaAs on transparent substrates. We demonstrate an active laser beam steering performed by single GaAs nanoantennas comprising an asymmetric dimer of two cylindrical nanoparticles. Obtained results show up to 7 degrees scattering tuning under a low pump fluence of 0.9 mJ cm^(-2). We also demonstrate an all-optical modulation of the deflection efficiency, performed by the metasurface consists of phased array GaAs nanoantennas, exhibiting up to 15% intensity change in the designed diffraction order. Finally we propose an on-chip device consist of asymmetric GaAs nanoantenna coupling light to the integrated waveguide with an optically tunable efficiency. Our findings manifest new controllable meta-structures revealing extended functionalities for nanophotonic active devices.