A sketch of the potential in the mirror surface vicinity is shown for the case of attractive (a) and repulsive (b) optical Fermi-potentials. The potential step at is equal to the mirror optical potential . The potential slope at is governed by the centrifugal effective acceleration . The regions, responsible for different type of resonances, are indicated with numbers: 1: long-living quasi-bound states, 2: surface waves, and 3: narrow over-barrier resonances.
