Phys.org October 19, 2020
Ultrafast nanophotonics is an emerging research field aimed at the development of nanodevices capable of light modulation with unprecedented speed. An international team of researchers (Italy, USA – Rice University) demonstrated that the inhomogeneous spacetime distribution of photogenerated hot carriers induces a transient symmetry breaking in a highly symmetric plasmonic metasurface. The process is fully reversible and results in a broadband transient dichroism with a recovery of the initial isotropic state in less than 1 ps, overcoming the speed bottleneck caused by slower (electron–phonon and phonon–phonon) relaxation processes. Their results pave the way to ultrafast dichroic devices for high-speed modulation of light polarization…read more. TECHNICAL ARTICLEÂ
… An ultrashort laser pulse (green) excites cross-shaped plasmonic structures, which rotate the polarity of a second light pulse (white) that arrives less one picosecond after the first. Credit: A. Assié