Ultrafast dynamics of light scattering in resonant GaAs nanoantennas

Active dielectric nanostructures have become one of the most popular trend lines in the modern dielectric nanophotonics due to great opportunities, which are offered by their numerous practical applications. Particularly, the concept of an optical switcher in nanophotonic circuitry can be realized by so-called all-optical mechanism, which could be carried out by a nanoantenna, such as an asymmetric dimer comprised of resonant nanoparticles made of material with high refractive index. In this case all-optical switching can be defined as the change of the trajectory of the femtosecond laser pulse after scattering on the nanoantenna, which was pumped by the other strong laser pulse. The realization of such effects would be a significant advance on the path to a novel technology. In this paper, we numerically demonstrate all-optical switching in the cylindrical asymmetric GaAs nanodimer, with the relaxation time of 10 ps and the deflection angle of the probe pulse of 7° for the relatively low intensities of the pumping.