SPECULAR VERSUS DIFFUSE REFLECTION OF ATOMS FROM AN EVANESCENT-WAVE MIRROR

We tested the specularity of the reflection of slow atoms from an evan escent-wave mirror at normal incidence. In two of the three prisms tha t we tested the atoms were reflected diffusely. This nonspecular refle ction appears to be correlated with the rms roughness of the surface s upporting the evanescent wave. Only the highest quality surface (rms r oughness of the order of 0.1 nm) leads to specular reflection. This di scovery imposes stringent limits on the use of these mirrors in atomic -optics experiments. (C) 1996 Optical Society of America