Hannover 2016 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 29: Quantum Gases: Bosons III
Q 29.6: Talk
Wednesday, March 2, 2016, 12:30–12:45, e001
Coupled Photon Condensates in Variable Trapping Potentials — •David Dung1, Christian Kurtscheid1, Tobias Damm1, Julian Schmitt1, Frank Vewinger1, Jan Klärs2, and Martin Weitz1 — 1Institut für Angewandte Physik, Universität Bonn — 2Institut für Quantenelektronik, ETH Zürich
We report on recent work to create multiple coupled photon condensates in a single microcavity setup at room-temperature. Bose-Einstein condensation has been observed for cold atomic gases, solid state quasiparticles as exciton-polaritons, and more recently with photons. The latter can be realized in a dye-filled optical microcavity. Number-conserving thermalization of photons in the dye-microcavity is achieved by multiple absorption and fluorescence processes on dye-molecules. The short mirror spacing in the microcavity creates a suitable ground state for condensation, equivalent to a non-vanishing effective photon mass. By locally thermo-optically changing the refractive index inside the microcavity an effective trapping potential for photons can be induced. For this, a focused external control laser beam locally heats an absorbing silicon layer implemented below one of the cavity mirror coatings, leading to a local refractive index change of a thermo-responsive polymer mixed with the dye solution. The range of depths and trapping frequencies one can adjust with this technique have been determined. We also present measurements on photon tunneling between the microsites in the system. Moreover, a temporally retarded effective photon self-interaction is observed.