Photon condensate

In a pumped dye-filled microcavity, photns thermalize with the dye molecules by repeated absorption and emission. For sufficiently strong pumping, a photonic Bose-Einstein condensate forms, where the majority of photons occupy the lowest-energy mode.

Master equation: photon number n_ν

^{J. Klaers, F. Vewinger, M. Weitz, Nat Phys. 6, 512 (2010)}

^{R. Bennett et al., Phys. Rev. Appl. 13, 044031 (2020)}