All-optical switching in a continuously operated and strongly coupled atom-cavity system

We experimentally demonstrate collective strong coupling, optical bi-stability (OB), and all-optical switching in a system consisting of ultracold 85 Rb atoms, trapped in a dark magneto-optical trap (DMOT), and coupled to an optical Fabry-Perot cavity. The strong coupling is established by measuring the vacuum Rabi splitting (VRS) of a weak on-axis probe beam. The dependence of VRS on the probe beam power is measured, and bi-stability in the cavity transmission is observed. We demonstrate control over the transmission of the probe beam through the atom-cavity system using a free-space off-axis control beam and show that the cavity transmission can be switched on and off in micro-second timescales using micro-Watt control powers. The utility of the system as a tool for sensitive, in-situ and rapid measurements is envisaged. Published by AIP Publishing.