Physical Review A
Slowing down of a guided light field along a nanofiber in a cold atomic gas
Fam Le Kien, K. Hakuta
Abstract
We develop a systematic formalism to study the propagation of a guided probe light field along a nanofiber embedded in a cold atomic gas. We derive a general axial propagation equation for the amplitude of the photon flux of the guided light, which allows us to take into account the complexity of the guided-field vector structure and the evanescent-wave nature of the guided-field transverse profile. We use our formalism to explore the possibility of slowing down of the guided light via the process of electromagnetically induced transparency. We show that, despite the effects of the spatially varying detuning, caused by the van der Waals potential, and the spatially varying atom-field coupling, caused by the evanescent-wave nature of the guided mode in the transverse plane, the group velocity of the guided light can be substantially reduced due to the steep dispersion of the atomic gas in the condition of electromagnetically induced transparency.