Light-induced atomic desorption for loading a sodium magneto-optical trap

Abstract

We report studies of photon-stimulated desorption, also known as light-induced atomic desorption, of sodium atoms from a vacuum-cell glass surface used for loading a magneto-optical trap (MOT). Fluorescence detection was used to record the trapped atom number and the desorption rate. We observed a steep wavelength dependence of the desorption process above 2.6 eV photon energy, a result significant for estimations of sodium vapor density in the lunar atmosphere. Our data fit well to a simple model for the loading of the MOT dependent only on the sodium desorption rate and residual gas density. Up to 3.7 × 10 7 Na atoms were confined under ultrahigh-vacuum conditions, creating promising loading conditions for a vapor-cell-based atomic Bose-Einstein condensate of sodium.

Light-induced atom desorption from glass surfaces characterized by X-ray photoelectron spectroscopy

“…LIAD rates are linearly dependent on the light intensity, which has also been reported in Ref. [16,17]. This linear dependence indicates that the observed LIAD is a one-photon process and is not caused by heating effects.…”

“…The LIAD rates increase monotonically with increasing photon energy for both substrates, as reported in Refs. [15,17,21]. The tendency is prominent for quartz: The rate at 4.3 eV is over 10 times higher than that at 3.1 eV, while at photon energies of 1.8 and 2.1 eV, the desorption signals are below the levels of background noise.…”

“…This phenomenon has attracted particular attention in laser cooling and trapping experiments using ultrahigh vacuum cells, into which atoms can be loaded quickly on demand from the surface by LIAD techniques [13,14]. However, most LIAD studies [13,[15][16][17][18][19] focused only on desorbed atoms, and lack of basic knowledge of the surface itself leads to a poor understanding of desorption mechanisms and also some contradictory practical information. For example, one group reported that LIAD from quartz glass is not effective [20], but another loaded a magneto-optical trap in a quartz cell by LIAD [16].…”

All-optical vapor density control for electromagnetically induced transparency

“…Until now, atomic photo-detachment from coated and uncoated surfaces allowed efficient loading of hollow-core fibers, magneto-optical traps, atom chips, and Bose-Einstein condensates [5][6][7][8][9]. Nonetheless, this technique has been limited to the generation of atomic bursts.…”

Low Energy Atomic Photodesorption from Organic Coatings

“…Therefore, either the organic compound is optimized for minimum contamination of the residual background pressure, or the light-desorption effect is obtained from other surfaces, including the glass or metallic walls of the vacuum chamber or thin metal layers [56,65,[67][68][69][70].…”