  We report a preliminary experimental study of EIT and stored light in the
high optical depth regime. In particular, we characterize two ways to mitigate
radiation trapping, a decoherence mechanism at high atomic density: nitrogen as
buffer gas, and a long, narrow cell geometry. Initial results show the promise
of both approaches in minimizing radiation trapping, but also reveal problems
such as optical pumping into trapped end-states. We also observe distortion in
EIT lineshapes at high optical depth, a result of interference from four-wave
mixing. Experimental results are in good qualitative agreement with theoretical
predictions.
