REFLECTION OF METASTABLE ARGON ATOMS FROM AN EVANESCENT-WAVE

The reflection of metastable argon atoms from evanescent waves produce d by total internal reflection and surface-plasmon excitation is inves tigated. We study the departure from ideal specular reflection by comp aring our experimental results with a Monte Carlo simulation of the re flection process. The observed broadening of the reflection beam was f ound to be caused predominantly by fluctuations of the dipole force. W e show that the surface plasmon produces significant enhancement of th e evanescent-wave intensity without degrading the quality of reflectio n. In addition, the number of spontaneous emissions occurring during t he reflection process was investigated by comparing the reflectivity o f evanescent-wave mirrors based on open and closed transitions in argo n. An open-transition mirror selectively reflects atoms which do not u ndergo spontaneous emission. For a large detuning, the average number of spontaneous emissions for reflected atoms was < 0.11.