Distribution of chromium atoms in 1-D optical molasses

In order to analyze effect of atomic distribution on deposition preparation of nanometer gratings under the action of collimated laser,based on semi-classical theory and Runge-Kutta numerical integration algorithm,the characteristics of dissipative force and the distribution of chromium atoms in 1-D optical molasses was discussed.Then the distribution of chromium atoms was simulated under different laser parameters.The results show that the best distribution appears when the detuning of the laser frequency equals to half of line width of chromium atoms.After the atom beam passing through 1-D optical molasses,its spatial width was suppressed to 0.43 times of that before and the atomic density becomes 1.79 times larger than before,under the condition that laser power equals to 40mW and laser detuning is-2.5MHz.This results show that the atomic distribution can be improved under the action of collimated laser and it's helpful for the deposition preparation of nanometer gratings.