Reply to "Comment on 'Stimulated Raman adiabatic passage from an atomic   to a molecular Bose-Einstein condensate'"
  In the Comment by M. Mackie \textit{et al.} [arXiv: physics/0212111 v.4], the authors suggest that the molecular conversion efficiency in atom-molecule STIRAP can be improved by lowering the initial atomic density, which in turn requires longer pulse durations to maintain adiabaticity. Apart from the fact that the mean-field approximation becomes questionable at low densities, we point out that a low-density strategy with longer pulses has several problems. It generally requires higher pulse energies, and increases radiative losses. We also show that even within the approximations used in the Comment, their example leads to no efficiency improvement compared to our high-density case. In a more careful analysis including radiative losses neglected in the Comment, the proposed strategy gives almost no conversion owing to the longer pulse durations required. 
P. D. Drummond, K. V. Kheruntsyan, D. J. Heinzen, and R. H. Wynar