Bose-Einstein condensation of photons in a long fiber cavity

We demonstrate photon Bose-Einstein condensation (photon-BEC) at a broad temperature range that is valid also in the long 1D fiber cavity limit. It is done with an erbiumytterbium co-doped fiber (EYDF) cavity by overcoming the challenging requirement of sublinear light dispersion for BEC in 1D using a chirped-gratings Fabry-Perot. We experimentally show with a square-root mode-dispersion, a quadratic temperature dependence of the critical power for condensation (compared to a linear dependence in finite regular fiber-cavities) between 90 K and 382 K, as the theory predicts. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

In this study, photon Bose-Einstein condensation was demonstrated over a broad temperature range, showing its validity in the long 1D fiber cavity limit. The experimental results confirmed a square-root mode-dispersion and a quadratic temperature dependence of the critical power for condensation between 90K and 382K.