Doppler cooling of buffer-gas-cooled barium monofluoride molecules

We demonstrate one-dimensional Doppler cooling of a beam of buffer-gas-cooled barium monofluoride (BaF) molecules. This represents a key step towards further cooling and trapping of BaF molecules. The dependencies of the cooling efficiency on the detuning of laser, the intensity of the laser, and the bias field are systematically studied. Furthermore, the numerical simulations with a Monte Carlo method agree quite well with our data.