Bose-Einstein Condensation of Photons and Periodic Potentials for Light

7 04/2015

Tuesday, 07 Apr. 2015, 13:00 - 14:00

Presenter: Martin Weitz; Institut für Angewandte Physik, Universität Bonn, Germany
Host: M. Aspelmeyer
Where: Schrödingerroom, 4th Floor, Boltzmanngasse 5, 1090 Wien

Bose-Einstein condensation has been observed in several physical systems, including cold atomic gases, exciton-polaritons, and magnons. Photons usually show no Bose-Einstein condensation, since for Planck’s blackbody radiation the particle number is not conserved and the photons at low temperatures vanish in the system walls. I here describe experiments with a dye-filled optical microresonator experimentally observing Bose-Einstein condensation of photons. Thermalization is achieved in a number conserving way by photon scattering off the dye molecules, and the cavity mirrors provide both an effective photon mass and a confining potential. I will also report on recent work realizing periodic lattice potentials for the photon gas.