sentences:  The correlation function associated with the spectral density of resonance fluorescence is reliant on the electric field.Thus once the constant K has been determined, the result is equivalent to
  
  formula_65
  
  This is related to the intensity by formula_66
  
  In the weak field limit when formula_67 the power spectrum can be determined to be
  
  formula_68.In the strong field limit, the power spectrum is slight more complicated and found to be
  
  formula_69.