Erlangen 2018 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 38: Poster: Quantum Optics and Photonics I
Q 38.3: Poster
Dienstag, 6. März 2018, 16:15–18:15, Orangerie
Calorimetry and Coherence of a Photon Bose-Einstein Condensate — •Erik Busley1, Julian Schmitt2, Tobias Damm1, David Dung1, Fahri Öztürk1, Christian Kurtscheid1, Jan Klärs3, Frank Vewinger1, and Martin Weitz1 — 1Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, D-53115 Bonn — 2Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, CB3 0HE Cambridge, United Kingdom — 3Faculty of Science and Technology, University of Twente, De Horst 2, 7522LW Enschede, Netherlands
We have in earlier work experimentally realized Bose-Einstein condensation of photons. The condensate is generated in a dye-filled optical microcavity which provides a photon dispersion equivalent to harmonically trapped massive bosons. Thermalization of the photon gas is achieved by subsequent absorption and emission cycles in the dye molecules which fulfill the Kennard-Stepanov relation.
Here we report on recent results regarding the caloric properties of the photon condensate. The specific heat shows a cusp singularity at the phase transition similar to liquid helium. Also, the internal energy per particle shows the expected behavior for a phase transition. More recently, we have investigated the first-order coherence of the photon gas below and above condensation threshold. Tunable Michelson and Mach-Zehnder interferometers are used to split up and recombine the cavity emission to obtain temporal and spatial coherence. The interferometrically measured coherence times range from picoseconds below criticality to microseconds above the condensation threshold.