Spectral density fluctuations , optically

One goal of the research in the Moerner group at IBM was the exploration of ultimate limits to the spectral hole-burning optical storage process. A particularly interesting limit on the SNR of a spectral hole results from the finite number of molecules that contribute to the absorption profile near the hole. Due to unavoidable number of fluctuations in the density of molecules in any spectral interval, there should exist a spectral noise on an inhomogeneous... 

Here the authors consider the possibility of inferring such statistical characteristics from the spectral features of probe photons or particles that are scattered by the density fluctuations of trapped atoms, notably in optical lattices, in two hitherto unexplored scenarios, (a) The probe is weakly (perturbatively) scattered by the local atomic density corresponding to the random occupancy of different lattice sites, (b) The probe is multiply scattered by an arbitrary (possibly unknown a priori) multi-atom distribution in the lattice. The highlight of the analysis, which is based on this random matrix approach, is the prediction of a semicircular spectral lineshape of the probe scattering in the large-fluctuation limit of trapped atomic ensembles. Thus far, the only known case of quasi-semicircular lineshapes in optical scattering has been predicted [Akulin 1993] and experimentally verified [Ngo 1994] in dielectric microspheres with randomly distributed internal scatterers. 

We consider the possibility of inferring such statistical characteristics from the spectral features of probe particles scattered by the density fluctuations (DF) of trapped atoms, notably in optical lattices (OL), in two hitherto unex-... 

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