qspec.saturation_intensity  (  f ,  a  )[source]

The saturation intensity of an electronic dipole transition $$ I_0 = \frac{\pi hf^3A_{ki}}{3c^2}. $$

Parameters:

farray_like

The frequency $f$ of the transition $|i\rangle\rightarrow|k\rangle$ (MHz).

aarray_like

The Einstein $A_{ki}$ coefficient (MHz).

Returns:

sat_intensityndarray

The saturation intensity $I_0$.