arXiv:1912.11358
Photon thermalization and a condensation phase transition in an electrically pumped semiconductor microresonat
S. Barland, Pierre Azam, Gian Luca Lippi, Robert A. Nyman, Robin Kaiser
Abstract
We report on an experimental study of photon thermalization and condensation in a semiconductor microresonator in the weak-coupling regime. We measure the dispersion relation of light and the photon mass in a single-wavelength, broad-area resonator. The observed luminescence spectrum is compatible with a room-temperature, thermal-equilibrium distribution. A phase transition, identified by a saturation of the population at high energies and a superlinear increase of the occupation at low energy, takes place when the phase-space density is of order unity. We explain our observations by Bose-Einstein condensation of photons in equilibrium with a particle reservoir and discuss the relation with laser emission.