The prospect of creating metamaterials with optical properties largely exceeding the parameter space covered by natural materials has been inspiring intense research efforts for more than a decade. Until recently, optical metamaterials were usually associated with plasmonic nanostructures. However, plasmonic metamaterials suffer from the intrinsic absorption losses of metals at optical frequencies. To overcome this problem, metamaterial research has shifted its focus towards nanoparticles composed of high refractive index dielectrics, which support electric and magnetic multipolar Mie-type resonances . Similar to plasmonic nanoresonators, their resonance properties can be tuned by the nanoparticle design, making them versatile building blocks of functional photonic nanostructures with tailored optical response. Silicon in particular has emerged as a popular material choice, not only due to its high refractive index and very low absorption losses in the telecom spectral range, but also to its huge technological relevance.
This talk will review our recent advances in controlling light with Mie-resonant metasurfaces - the two-dimensional counterparts of metamaterials - composed of Mie-resonant silicon nanoparticles. Such metasurfaces can impose a spatially variant phase shift onto an incident light field, thereby providing control over its wave front with high transmittance efficiency . A focus of this talk will be on strategies to obtain dynamic control of the metasurface optical response .
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