School of Physics Colloquia

Monday 5 February 2018

Professor Albert Polman,Center for Nanophotonics, AMOLF, Amsterdam, the Netherlands
Time-resolved cathodoluminescence spectroscopy of optical metasurfacess

Abstract: A fast electron beam passing through the surface of a polarizable material generates a single-cycle electric field oscillation near the surface that couples strongly to the free or bound electrons in the material. The ultrafast field oscillation presents a spectrally broadband excitation from deep UV to near IR, and the nanoscale electron probe size results in deep-subwavelength spatial excitation resolution. As such, electron beam excitation is one of the purest forms of optical excitation, directly addressing the quantum nature of optical matter. We study the generation of femtosecond plasmonic and photonic wave packets on metallic and dielectric metasurfaces by a 30 keV electron beam. We measure the angular radiation profile of optical metasurfaces and reconstruct the optical band structure, and determine the full polarization state of the emitted light. Finally, we introduce our newly built time-resolved cathodoluminescence microscope and present measurements of photon bunching statistics.

3:00pm, Slade Lecture Theatre, Physics Building A28

Cake and coffee are served at all School Colloquia.

Future Colloquia

26 February 2018 – Yvonne Wong (UNSW)