Single atoms coupled to a near-concentric cavity
Chi Huan Nguyen, Adrian Nugraha Utama, Nick Lewty, Kadir Durak, Gleb Maslennikov, Stanislav S. Straupe, Matthias Steiner, Christian Kurtsiefer · Physical Review A · 2017
Concentric cavities can lead to strong photon-atom coupling without a need for high finesse or small physical-cavity volume. In this proof-of-principle experiment we demonstrate coupling of single Rb atoms to an 11-mm-long near-concentric cavity with a finesse $F=138(2)$. Operating the cavity $1.7(1)\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{m}$ shorter than the critical length, we observe an atom-cavity coupling constant ${g}_{0}=2\ensuremath{\pi}\ifmmode\times\else\texttimes\fi{}5.0(2)$ MHz which exceeds the natural dipole decay rate $\ensuremath{\gamma}$ by a factor of ${g}_{0}/\ensuremath{\gamma}=1.7(1)$.