A laser source (100) is intended for a device for interacting simultaneously with several atomic species within time intervals which are common to these species. The laser source includes a laser radiation generating set (1), an optical amplifier (2), and a frequency doubler set (3). A component for time-division multiplexing (5) assign in alternation at successive time sub-intervals, initial radiations corresponding to interaction radiations dedicated to different atomic species. The result of the interactions with one of the atomic species is then identical to the result of the interactions with a continuous radiation dedicated to the atomic species.