Saturation of the absorption of light by an atom captured in a trap

A nonlinear (in respect of the field) correction is found to the cross section for the absorption of light by a trapped atom. When the line half-width is much less than the frequency of vibrations of an atom in a trap, this correction is smaller compared with an untrapped atom by a factor which is equal to the Doppler width divided by the frequency of the atomic vibrations.