Electromagnetically Induced Transparency in Rubidium-Filled HC-PCF

This paper report the observation of electromagnetically induced transparency (EIT) in Rb-filled HC-PCF. We observe EIT in a lambda energy-level configuration with narrow linewidth, in contrast to that obtained by Ghosh et al. (2006). The fibre used in this experiment is large-pitch kagome-structured HC-PCF (Couny et al., 2006), with a core diameter of 11 mum. In order to prevent rubidium from being quickly adsorbed onto the silica walls, the fibre core was coated with PDMS by first filling it with a solution of 2% PDMS in diethyl-ether, and then evaporating the ether. The PDMS wall coating has a strongly beneficial effect in suppressing these dephasing collisions but further measurements at much lower coupling intensities are necessary to quantify how small the dephasing due to the coated wall is.