Analysing the atom-surface interaction through nanocell spectroscopy

In this paper, the strong van der Waals (vW) shift induced on high-lying excited states is investigated, such as Cs(6D), that is probed at 917 nm (6D₅2/) or 921 nm (6D₃2/) after a prior excitation on the Cs D₂ line 6S₁2/→6P₃2/ at 852 nm. The analysis currently encompass a 40-130 nm range of thickness, leading to the observation of frequency shifts-relatively to the transition frequency in the free-space- as large as -∼10 GHz. The van der Waals potential between two walls is predicted to obey a transcendental Lerch function, as a result of the induced multiple "electric images", and to follow a L dependence (L : the local thickness).