In physics, an atomic mirror is a device which reflects neutral atoms in a way similar to the way a conventional mirror reflects visible light. Atomic mirrors can be made of electric fields or magnetic fields, electromagnetic waves or just silicon wafer ; in the last case, atoms are reflected by the attracting tails of the van der Waals attraction (see quantum reflection). Such reflection is efficient when the normal component of the wavenumber of the atoms is small or comparable to the effective depth of the attraction potential (roughly, the distance at which the potential becomes comparable to the kinetic energy of the atom). To reduce the normal component, most atomic mirrors are blazed at the grazing incidence.