to the atomic transition. This explains the observation of the blue peak in the experiment as shown in the Figs. \[atnogrid\](a), \[motpowgrid\] and \[pol\](b). This blue peak is unpolarised as the fluorescence can be of any polarisation.

Comparing the numbers in the above calculations and the experiment, the total intensity of all the MOT beams and dipole moment for isotropic beam case gives $\Omega/(2\pi) \approx 6$ MHz as an estimate. However, theoretical treatment is for single drive beam whereas there are six beams, all with different polarisation and non-zero relative phase difference between them. The calculation therefore is a lower estimate of the light-atom interaction, since sub-Doppler cooling mechanisms will try to localise atoms towards intensity maxima formed by the six MOT beams increasing effective value of $\Omega$ [@townsend_phase-space_1995]. In addition, for the analysis we have assumed the cavity field to be very weak, such that the atomic coherence, $\rho$ is only first order in cavity field, $\alpha$. There is a possibility of gain to be higher order in $\alpha$ which has not been considered here. Hence exact quantitative comparison is not possible with the present model, but qualitatively we do not expect the physics behind the observations to change.

