We systematically study stationary light pulses formed in cold atomic media based on the effect of electromagnetically induced transparency (EIT) with counterpropagating laser fields. In contrast to hot media, the formation of stationary light in cold media is not straightforward. Detrimental coherences of high spatial frequencies can be excited which are naturally suppressed in hot media. We demonstrate numerically that these excitations prevent the formation of stationary light in cold media. We further present numerical and experimental results which show that these excitations can be dynamically suppressed in a medium of nonstationary atoms by reducing the width of the EIT transparency window below the typical Doppler shifts present in the medium. This provides an increased interaction time of the light pulses with the medium and enhances the efficiency of nonlinear optical interactions.

• Received 29 November 2011

DOI:https://doi.org/10.1103/PhysRevA.85.023838