Atomic resonance behavior in laser-induced Rb atom desorption—the effect of ambient gas atoms and molecules

We report an observation that in a typical optical pumping cell containing Rb metal and 150 Torr N2 gas, a cw laser beam of a few tens of mW and beam size 5.5 mm2 can desorb Rb films on cell surfaces when the laser is tuned to the Rb D1 line. The frequency dependence of the Rb desorption rate displays atomic resonance behavior. The desorption is suggested to be mediated by the ambient gas atoms (Rb) and molecules (N2). The phenomenon was used to provide evidence for the existence of thin Rb films on seemingly clear cell surfaces.