Publications

Polarization-Independent Silicon Metadevices for Efficient Optical Wavefront Control

Chong, Katie E.; Staude, Isabelle; James, Anthony R.; Dominguez, Jason J.; Liu, Sheng L.; Campione, Salvatore; Subramania, Ganapathi S.; Luk, Ting S.; Decker, Manuel; Neshev, Dragomir N.; Brener, Igal B.; Kivshar, Yuri S.

We experimentally demonstrate a functional silicon metadevice at telecom wavelengths that can efficiently control the wavefront of optical beams by imprinting a spatially varying transmittance phase independent of the polarization of the incident beam. Near-unity transmittance efficiency and close to 0-2 phase coverage are enabled by utilizing the localized electric and magnetic Mie-type resonances of low-loss silicon nanoparticles tailored to behave as electromagnetically dual-symmetric scatterers. We apply this concept to realize a metadevice that converts a Gaussian beam into a vortex beam. The required spatial distribution of transmittance phases is achieved by a variation of the lattice spacing as a single geometric control parameter.