All?Optical Modulation with Dielectric Nanoantennas: Multiresonant Control and Ultrafast Spatial Inhomogeneities

The transient optical response of multiresonant all-dielectric nanoantennas via a combination broadband ultrafast reflectivity experiments and nonlinear optics nanoscale modeling is studied. Ultrafast all-optical control the demonstrated in variably sized Al .18 Ga .82 As over four distinct Mie resonances (including Fano-like resonances), spanning broad spectral range, from red to near-infrared. A spatially inhomogeneous dynamical model, which accounts for diffusion photogenerated carriers inside semiconductor, introduced exploited isolate physical phenomena leading overall response, namely, Drude plasma formation Pauli blocking following band filling thermo-optical effect. results pave way development multiwavelength all-optically reconfigurable filters next-generation add/drop multiplexing.