Structuring visible light with dielectric metasurfaces
11:00 - 12:00 noon
Rm 4475, 4/F (Lift 25, 26), Academic Complex, HKUST


Vortex beams generation with dielectric metasurface - Metasurfaces provides us with the unique capability to fully control light with planar elements. Recently, there has been increasing interest in using dielectric materials, like TiO2, in order to reduce losses and undesired polarization conversion, just to name some advantages over metallic nano-structures. In 2017, we realized a dielectric metasurface q-plate that produces visible vortex light beams whose handedness depend by the polarization handedness of the illuminating light [1]. We then generalized the concept by realizing a dielectric metasurface (J-plate) that converts arbitrary light spin states into arbitrary total angular momentum states [2].
I will present the most recent results from the research topic of designing dielectric metasurfaces for structuring light.  

  1. Devlin, R.C., Ambrosio, A., et al. Spin-to-orbital angular momentum conversion in dielectric metasurfaces. Optics Express 25, 1, 377-393 (2017).
  2. Devlin, R.C., Ambrosio, A., et al. Arbitrary spin-to-orbital angular momentum conversion of light. Science 358, 896-901 (2017).


Speaker's Biography

Antonio Ambrosio was born in Ottaviano, Italy, in June 19, 1979. He received his Master Degree in Condensed Matter Physics from the University of Napoli “Federico II”, Italy. In 2006, he received his PhD degree in Applied Physics from the University of Pisa, Italy.

From 2006 – 2013 he worked at Consiglio Nazionale delle Ricerche (CNR), the Italian Research Council, focusing on developing high-resolution optical microscopy techniques and investigating the light-driven surface structuring of azobenzene-containing polymer films. 

In April 2013, Dr. Ambrosio started collaborating with Prof. Federico Capasso group at Harvard University as a Visiting Research Scholar of the John A. Paulson School of engineering and Applied Sciences. At Harvard, Dr. Ambrosio built a nano-imaging spectroscopical facility that allows optical imaging with 50nm resolution in a broad wavelength range (from 450nm to 1.7um), for instance the steering of surface plasmon polaritons in one- and two-dimensional metamaterials. At Harvard, Dr. Ambrosio also started working on dielectric metasurfaces, that allow controlling light in its amplitude, phase and polarization in ways that are not reproducible with standard optical components. 
Since July 2016, Dr. Ambrosio Principal Scientist at the Center for Nanoscale Systems at Harvard University where he established the Optical Nano-imaging Lab. that he is leading in the research activity about the development of new optical near-field imaging and spectroscopy techniques for 2D materials, polymers and nanostructured surfaces.

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11:00 - 12:00 noon
Rm 4475, 4/F (Lift 25, 26), Academic Complex, HKUST
讲者/ 表演者:
Dr. Antonio Ambrosio