A Rayleigh vs Raman scattering for low saturation

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In a three-level atomic system with two ground states and one excited state, the discussion focuses on the dominance of Rayleigh scattering over Raman scattering under low saturation conditions. The driving field is highly detuned, resulting in a negligible probability of excitation to the excited state. While Rayleigh scattering is characterized as coherent scattering, the potential for Raman transitions to the second ground state complicates the analysis, as these transitions involve a frequency change but maintain coherence. The user seeks a method to calculate the rates of Rayleigh versus Raman scattering, given the assumption of equal dipole moment coupling between the excited state and both ground states. The inquiry highlights the need for a deeper understanding of the interactions in this specific quantum system.
BillKet
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Hello! I have the following situation: I have a 3 level system, with 2 ground states, call them ##g_1## and ##g_2## and an excited state, ##e##, with energies ##E_{g1}<E_{g2}## and ##E_e##. I have a driving field with frequency ##\omega## such that ##\Gamma \ll \Delta \ll E_{g2}-E_{g1} \ll E_e - E_{g1}##, where ##\Gamma## is the linewidth of the excited state and ##\Delta## is the detuning of the excited state from the ##g_1\to e## transition. So basically the laser is very detuned from any transition in the system and we can assume that the laser power is small enough such that the saturation parameter, ##s## is much smaller than 1, so the probability of the atom getting excited to ##e## is virtually zero. I found in AMO books that in this case Rayleigh scattering dominates i.e. coherent scattering, compared to incoherent scattering i.e. decays from ##e## and the ratio of the 2 rates is ##\sim s##. However, as far as I can tell, these derivations don't take into account Raman transitions to ##g_2## (assuming we start in ##g_1##) in which ##e## doesn't get excited. These kinds of transitions are not Rayleigh (as the light frequency changes), but they are also not incoherent, as there is still a clear phase between the driving field and the emitted photon (but they have different frequencies). So, given my situation, how can I calculate the Rayleigh scattering rate vs Raman scattering rate (i.e. with both of them coherent processes and assuming that the dipole moment coupling between ##e## and ##g_1## is the same as the one between ##e## and ##g_2##)? Thank you!
 
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