With the advent of nanofabrication and imaging at the nanoscale, many unexpected properties of thermal radiation have been explored in the last twenty years. It is now possible to design plasmonic and dielectric metasurfaces controlling the spectrum, polarization and directivity of emitted radiation. These concepts developped for thermal radiation can be extended to fluorescence due to thermalized ensembles of emitters such as dye molecules or quantum dots .
The first part of the talk will be devoted to an incandescent thermal metasurface source that can be modulated beyond 10 MHz, six orders of magnitude faster than commercially available hot membranes . In the second part of the talk, I will discuss fundamental issues related to spontaneous emission by thermalized systems. I will present a general absorption-coherence relation . This relation will be used to analyse the origin of spatial coherence in light emitted by dye molecules in strong coupling with surface plasmons .
1. Light emission by nonequilibrium bodies: local Kirchhoff law, J.J. Greffet, P. Bouchon, G. Brucoli, F. Marquier, Phys.Rev.X 8, 021008 (2018).
2. An incandescent metasurface for quasimonochromatic polarized Mid-Wave Infrared emission modulated beyond 10 MHz, L. Wojszvzyk, A. Nguyen, Anne-Lise Coutrot, C. Zhang, B. Vest, J.J. Greffet, Nat. Commun 12, 1492 (2021).
3. General relation between spatial coherence and absorption, D. Tihon, S. Withington, E. Bailly, B. Vest and J.J. Greffet, Opt. Expr. 29, 425 (2021).
4. Spatial coherence of light emitted by thermalized ensembles of emitters coupled to surface waves, Elise Bailly , Jean-Paul Hugonin, Benjamin Vest , and Jean-Jacques Greffet, Phys.Rev.Res. 3, L032040, (2021).
Bio: Jean-Jacques Greffet received his PhD in solid state physics in 1988 from Université Paris-Sud. He is a professor at Institut d'Optique, Université Paris-Saclay and a senior member of Institut Universitaire de France. He first worked on light scattering of electromagnetic waves and the theory of near-field microscopy. He revisited thermal emission at the nanoscale and discovered the role of surface waves to produce spatially coherent thermal sources and to enhance near-field radiative heat transfer. He made contributions to the field of nanoantennas including the proposal for using nanoantennas with single quantum emitters to control lifetime and directional emission. His current research interests deal with revisiting fundamental quantum optics experiments with surface plasmons (wave-particle duality, Hong Ou Mandel experiment, photon-plasmon entanglement, electrical emission by tunnel effect), controlling light-matter interaction at the nanoscale using resonators and collective effects and exploring novel light sources using metasurfaces. He is an OSA fellow and the recipient of the Servant prize of the French Academy of Science.
This seminar is sponsored by the Department of Applied Physics and the Ginzton Laboratory