Physical Review A
Quantitative measurements of light-induced desorption of rubidium atoms from quartz substrates
K. Kitagami, K. Hosumi, K. Goto, A. Hatakeyama
Abstract
We investigated the light-induced desorption (LID) of Rb atoms from quartz substrates to understand better the LID observed in alkali-metal vapor cells used in laser cooling experiments. The substrate was first exposed to Rb under ultrahigh vacuum conditions. The Rb was found to diffuse into the substrate by x-ray photoelectron spectroscopy. Rb atoms were then deposited with a density of $\ensuremath{\sim}{10}^{15}$ atoms/cm${}^{2}$ on the surface, from which LID was observed upon irradiation by ultraviolet light. The LID rate depended linearly on the light intensity in the investigated range up to 15 mW/cm${}^{2}$. A typical value was ${10}^{10}$ atoms/(s cm${}^{2}$) per mW/cm${}^{2}$ at a photon energy of 4.3 eV (290 nm in wavelength). We found that the LID rate increased with photon energy in the range 1.8--4.3 eV (700--290 nm in wavelength).